should not use unkeyed fields anyway.

.github/workflows/ci.yml

@@ -1,33 +0,0 @@
-name: "Continuous Integration"
-
-on:
-  workflow_dispatch:
-  push:
-    branches: [ main ]
-    paths: [ "*.go" ]
-  pull_request:
-    branches: [ main ]
-    paths: [ "*.go" ]
-
-jobs:
-  ci:
-    name: "Tests"
-    runs-on: ubuntu-latest
-
-    env:
-      GOOS: "linux"
-      GOARCH: "amd64"
-      GO111MODULE: "on"
-      CGO_ENABLED: "0"
-
-    steps:
-    - name: Set up Go
-      uses: actions/setup-go@v3
-      with:
-        go-version: 1.21
-
-    - name: Check out go-incr
-      uses: actions/checkout@v3
-
-    - name: Run all tests
-      run: go test ./...

.gitignore

@@ -1,20 +1 @@
-# Binaries for programs and plugins
-*.exe
-*.dll
-*.so
-*.dylib
-
-# Test binary, build with `go test -c`
-*.test
-
-# Output of the go coverage tool, specifically when used with LiteIDE
-*.out
-
-# Project-local glide cache, RE: https://github.com/Masterminds/glide/issues/736
-.glide/
-
-# Other
 .vscode
-.DS_Store
-coverage.html
-.idea

.travis.yml

@@ -0,0 +1,13 @@
+language: go
+
+go:
+  - 1.6.2
+
+sudo: false
+
+before_script:
+  - go get -u github.com/blendlabs/go-assert
+  - go get ./...
+
+script:
+  - go test ./...

COVERAGE

@@ -1 +0,0 @@
-29.02

LICENSE

@@ -1,7 +1,6 @@
 MIT License
 
 Copyright (c) 2016 William Charczuk.
-Copyright (c) 2024 Zeni Kim.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

Makefile

@@ -1,10 +1,9 @@
-all: new-install test
-
-new-install:
-	@go get -v -u ./...
-
-generate:
-	@go generate ./...
+all: test
 
 test:
-	@go test ./...
+	@go test ./...
+
+cover:
+	@go test -short -covermode=set -coverprofile=profile.cov
+	@go tool cover -html=profile.cov
+	@rm profile.cov

PROFANITY_RULES.yml

@@ -1,4 +0,0 @@
-go-sdk:
-  excludeFiles: [ "*_test.go" ]
-  importsContain: [ github.com/blend/go-sdk/* ]
-  description: "please don't use go-sdk in this repo"

README.md

@@ -1,55 +1,55 @@
 go-chart
 ========
+[![Build Status](https://travis-ci.org/wcharczuk/go-chart.svg?branch=master)](https://travis-ci.org/wcharczuk/go-chart)[![Go Report Card](https://goreportcard.com/badge/github.com/wcharczuk/go-chart)](https://goreportcard.com/report/github.com/wcharczuk/go-chart)
 
-This project starts from a full copy from [https://git.smarteching.com/zeni/go-chart](https://git.smarteching.com/zeni/go-chart). 28 Oct 2024.
+Package `chart` is a very simple golang native charting library that supports timeseries and continuous
+line charts. 
 
--
+The v1.0 release has been tagged so things should be more or less stable, if something changes please log an issue.
 
-Master should now be on the v3.x codebase, which overhauls the api significantly. Per usual, see `examples` for more information.
+Master should now be on the v2.x codebase, which brings a couple new features and better handling of basics like axes labeling etc. Per usual, see `_examples` for more information.
 
 # Installation
 
 To install `chart` run the following:
 
 ```bash
-> go get git.smarteching.com/zeni/go-chart/v2@latest
+> go get -u github.com/wcharczuk/go-chart
 ```
 
-Most of the components are interchangeable so feel free to crib whatever you want.
+Most of the components are interchangeable so feel free to crib whatever you want. 
 
-# Output Examples
+# Output Examples 
 
 Spark Lines:
 
-![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/tvix_ltm.png)
+![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/tvix_ltm.png)
 
 Single axis:
 
-![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/goog_ltm.png)
+![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/goog_ltm.png)
 
 Two axis:
 
-![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/two_axis.png)
+![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/two_axis.png)
 
 # Other Chart Types
 
 Pie Chart:
 
-![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/pie_chart.png)
+![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/pie_chart.png)
 
-The code for this chart can be found in `examples/pie_chart/main.go`.
+The code for this chart can be found in `_examples/pie_chart/main.go`.
 
 Stacked Bar:
 
-![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/stacked_bar.png)
+![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/stacked_bar.png)
 
-The code for this chart can be found in `examples/stacked_bar/main.go`.
+The code for this chart can be found in `_examples/stacked_bar/main.go`.
 
 # Code Examples
 
-Actual chart configurations and examples can be found in the `./examples/` directory. They are simple CLI programs that write to `output.png` (they are also updated with `go generate`.
-
-If folder ends in "web", has web servers, so start them with `go run main.go` then access `http://localhost:8080` to see the output.
+Actual chart configurations and examples can be found in the `./_examples/` directory. They are web servers, so start them with `go run main.go` then access `http://localhost:8080` to see the output.
 
 # Usage
 
@@ -61,7 +61,7 @@ import (
     ...
     "bytes"
     ...
-    "git.smarteching.com/zeni/go-chart/v2" //exposes "chart"
+    "github.com/wcharczuk/go-chart" //exposes "chart"
 )
 
 graph := chart.Chart{
@@ -83,7 +83,8 @@ Here, we have a single series with x range values as float64s, rendered to a PNG
 
 # API Overview
 
-Everything on the `chart.Chart` object has defaults that can be overriden. Whenever a developer sets a property on the chart object, it is to be assumed that value will be used instead of the default.
+Everything on the `chart.Chart` object has defaults that can be overriden. Whenever a developer sets a property on the chart object, it is to be assumed that value will be used instead of the default. One complication here
+is any object's root `chart.Style` object (i.e named `Style`) and the `Show` property specifically, if any other property is set and the `Show` property is unset, it is assumed to be it's default value of `False`.
 
 The best way to see the api in action is to look at the examples in the `./_examples/` directory.
 
@@ -95,4 +96,4 @@ The goal with the API itself is to have the "zero value be useful", and to requi
 
 # Contributions
 
-Contributions are welcome though this library is in a holding pattern for the forseable future.
+This library is super early but contributions are welcome.

_colors/colors_extended.txt

@@ -1,147 +0,0 @@
-aliceblue 	#f0f8ff 	240,248,255
-antiquewhite 	#faebd7 	250,235,215
-aqua 	#00ffff 	0,255,255
-aquamarine 	#7fffd4 	127,255,212
-azure 	#f0ffff 	240,255,255
-beige 	#f5f5dc 	245,245,220
-bisque 	#ffe4c4 	255,228,196
-black 	#000000 	0,0,0
-blanchedalmond 	#ffebcd 	255,235,205
-blue 	#0000ff 	0,0,255
-blueviolet 	#8a2be2 	138,43,226
-brown 	#a52a2a 	165,42,42
-burlywood 	#deb887 	222,184,135
-cadetblue 	#5f9ea0 	95,158,160
-chartreuse 	#7fff00 	127,255,0
-chocolate 	#d2691e 	210,105,30
-coral 	#ff7f50 	255,127,80
-cornflowerblue 	#6495ed 	100,149,237
-cornsilk 	#fff8dc 	255,248,220
-crimson 	#dc143c 	220,20,60
-cyan 	#00ffff 	0,255,255
-darkblue 	#00008b 	0,0,139
-darkcyan 	#008b8b 	0,139,139
-darkgoldenrod 	#b8860b 	184,134,11
-darkgray 	#a9a9a9 	169,169,169
-darkgreen 	#006400 	0,100,0
-darkgrey 	#a9a9a9 	169,169,169
-darkkhaki 	#bdb76b 	189,183,107
-darkmagenta 	#8b008b 	139,0,139
-darkolivegreen 	#556b2f 	85,107,47
-darkorange 	#ff8c00 	255,140,0
-darkorchid 	#9932cc 	153,50,204
-darkred 	#8b0000 	139,0,0
-darksalmon 	#e9967a 	233,150,122
-darkseagreen 	#8fbc8f 	143,188,143
-darkslateblue 	#483d8b 	72,61,139
-darkslategray 	#2f4f4f 	47,79,79
-darkslategrey 	#2f4f4f 	47,79,79
-darkturquoise 	#00ced1 	0,206,209
-darkviolet 	#9400d3 	148,0,211
-deeppink 	#ff1493 	255,20,147
-deepskyblue 	#00bfff 	0,191,255
-dimgray 	#696969 	105,105,105
-dimgrey 	#696969 	105,105,105
-dodgerblue 	#1e90ff 	30,144,255
-firebrick 	#b22222 	178,34,34
-floralwhite 	#fffaf0 	255,250,240
-forestgreen 	#228b22 	34,139,34
-fuchsia 	#ff00ff 	255,0,255
-gainsboro 	#dcdcdc 	220,220,220
-ghostwhite 	#f8f8ff 	248,248,255
-gold 	#ffd700 	255,215,0
-goldenrod 	#daa520 	218,165,32
-gray 	#808080 	128,128,128
-green 	#008000 	0,128,0
-greenyellow 	#adff2f 	173,255,47
-grey 	#808080 	128,128,128
-honeydew 	#f0fff0 	240,255,240
-hotpink 	#ff69b4 	255,105,180
-indianred 	#cd5c5c 	205,92,92
-indigo 	#4b0082 	75,0,130
-ivory 	#fffff0 	255,255,240
-khaki 	#f0e68c 	240,230,140
-lavender 	#e6e6fa 	230,230,250
-lavenderblush 	#fff0f5 	255,240,245
-lawngreen 	#7cfc00 	124,252,0
-lemonchiffon 	#fffacd 	255,250,205
-lightblue 	#add8e6 	173,216,230
-lightcoral 	#f08080 	240,128,128
-lightcyan 	#e0ffff 	224,255,255
-lightgoldenrodyellow 	#fafad2 	250,250,210
-lightgray 	#d3d3d3 	211,211,211
-lightgreen 	#90ee90 	144,238,144
-lightgrey 	#d3d3d3 	211,211,211
-lightpink 	#ffb6c1 	255,182,193
-lightsalmon 	#ffa07a 	255,160,122
-lightseagreen 	#20b2aa 	32,178,170
-lightskyblue 	#87cefa 	135,206,250
-lightslategray 	#778899 	119,136,153
-lightslategrey 	#778899 	119,136,153
-lightsteelblue 	#b0c4de 	176,196,222
-lightyellow 	#ffffe0 	255,255,224
-lime 	#00ff00 	0,255,0
-limegreen 	#32cd32 	50,205,50
-linen 	#faf0e6 	250,240,230
-magenta 	#ff00ff 	255,0,255
-maroon 	#800000 	128,0,0
-mediumaquamarine 	#66cdaa 	102,205,170
-mediumblue 	#0000cd 	0,0,205
-mediumorchid 	#ba55d3 	186,85,211
-mediumpurple 	#9370db 	147,112,219
-mediumseagreen 	#3cb371 	60,179,113
-mediumslateblue 	#7b68ee 	123,104,238
-mediumspringgreen 	#00fa9a 	0,250,154
-mediumturquoise 	#48d1cc 	72,209,204
-mediumvioletred 	#c71585 	199,21,133
-midnightblue 	#191970 	25,25,112
-mintcream 	#f5fffa 	245,255,250
-mistyrose 	#ffe4e1 	255,228,225
-moccasin 	#ffe4b5 	255,228,181
-navajowhite 	#ffdead 	255,222,173
-navy 	#000080 	0,0,128
-oldlace 	#fdf5e6 	253,245,230
-olive 	#808000 	128,128,0
-olivedrab 	#6b8e23 	107,142,35
-orange 	#ffa500 	255,165,0
-orangered 	#ff4500 	255,69,0
-orchid 	#da70d6 	218,112,214
-palegoldenrod 	#eee8aa 	238,232,170
-palegreen 	#98fb98 	152,251,152
-paleturquoise 	#afeeee 	175,238,238
-palevioletred 	#db7093 	219,112,147
-papayawhip 	#ffefd5 	255,239,213
-peachpuff 	#ffdab9 	255,218,185
-peru 	#cd853f 	205,133,63
-pink 	#ffc0cb 	255,192,203
-plum 	#dda0dd 	221,160,221
-powderblue 	#b0e0e6 	176,224,230
-purple 	#800080 	128,0,128
-red 	#ff0000 	255,0,0
-rosybrown 	#bc8f8f 	188,143,143
-royalblue 	#4169e1 	65,105,225
-saddlebrown 	#8b4513 	139,69,19
-salmon 	#fa8072 	250,128,114
-sandybrown 	#f4a460 	244,164,96
-seagreen 	#2e8b57 	46,139,87
-seashell 	#fff5ee 	255,245,238
-sienna 	#a0522d 	160,82,45
-silver 	#c0c0c0 	192,192,192
-skyblue 	#87ceeb 	135,206,235
-slateblue 	#6a5acd 	106,90,205
-slategray 	#708090 	112,128,144
-slategrey 	#708090 	112,128,144
-snow 	#fffafa 	255,250,250
-springgreen 	#00ff7f 	0,255,127
-steelblue 	#4682b4 	70,130,180
-tan 	#d2b48c 	210,180,140
-teal 	#008080 	0,128,128
-thistle 	#d8bfd8 	216,191,216
-tomato 	#ff6347 	255,99,71
-turquoise 	#40e0d0 	64,224,208
-violet 	#ee82ee 	238,130,238
-wheat 	#f5deb3 	245,222,179
-white 	#ffffff 	255,255,255
-whitesmoke 	#f5f5f5 	245,245,245
-yellow 	#ffff00 	255,255,0
-yellowgreen 	#9acd32 	154,205,50

_examples/annotations/main.go

@@ -1,14 +1,13 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
+
 	/*
 	   In this example we add an `Annotation` series, which is a special type of series that
 	   draws annotation labels at given X and Y values (as translated by their respective ranges).
@@ -38,7 +37,11 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/axes/main.go

@@ -1,14 +1,12 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	chart "git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 	   The below will draw the same chart as the `basic` example, except with both the x and y axes turned on.
@@ -17,14 +15,19 @@ func main() {
 
 	graph := chart.Chart{
 		XAxis: chart.XAxis{
-			Name: "The XAxis",
+			Style: chart.Style{
+				Show: true, //enables / displays the x-axis
+			},
 		},
 		YAxis: chart.YAxis{
-			Name: "The YAxis",
+			Style: chart.Style{
+				Show: true, //enables / displays the y-axis
+			},
 		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
+					Show:        true,
 					StrokeColor: chart.GetDefaultColor(0).WithAlpha(64),
 					FillColor:   chart.GetDefaultColor(0).WithAlpha(64),
 				},
@@ -34,7 +37,11 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/axes_labels/main.go

@@ -1,14 +1,12 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	chart "git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 	   The below will draw the same chart as the `basic` example, except with both the x and y axes turned on.
@@ -16,9 +14,20 @@ func main() {
 	*/
 
 	graph := chart.Chart{
+		XAxis: chart.XAxis{
+			Name:      "The XAxis",
+			NameStyle: chart.StyleShow(),
+			Style:     chart.StyleShow(),
+		},
+		YAxis: chart.YAxis{
+			Name:      "The YAxis",
+			NameStyle: chart.StyleShow(),
+			Style:     chart.StyleShow(),
+		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
+					Show:        true,
 					StrokeColor: chart.GetDefaultColor(0).WithAlpha(64),
 					FillColor:   chart.GetDefaultColor(0).WithAlpha(64),
 				},
@@ -28,7 +37,11 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/bar_chart/main.go

@@ -1,26 +1,26 @@
 package main
 
-//go:generate go run main.go
-
 import (
 	"fmt"
 	"log"
 	"net/http"
 	"os"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
-	graph := chart.BarChart{
-		Title: "Test Bar Chart",
-		Background: chart.Style{
-			Padding: chart.Box{
-				Top: 40,
-			},
-		},
+	sbc := chart.BarChart{
 		Height:   512,
 		BarWidth: 60,
+		XAxis: chart.Style{
+			Show: true,
+		},
+		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true,
+			},
+		},
 		Bars: []chart.Value{
 			{Value: 5.25, Label: "Blue"},
 			{Value: 4.88, Label: "Green"},
@@ -33,11 +33,10 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 	}
 
 	res.Header().Set("Content-Type", "image/png")
-	err := graph.Render(chart.PNG, res)
+	err := sbc.Render(chart.PNG, res)
 	if err != nil {
 		fmt.Printf("Error rendering chart: %v\n", err)
 	}
-
 }
 
 func port() string {

_examples/basic/main.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/wcharczuk/go-chart"
+)
+
+func drawChart(res http.ResponseWriter, req *http.Request) {
+	graph := chart.Chart{
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
+				YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func drawChartWide(res http.ResponseWriter, req *http.Request) {
+	graph := chart.Chart{
+		Width: 1920, //this overrides the default.
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
+				YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.HandleFunc("/wide", drawChartWide)
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}

_examples/custom_formatters/main.go

@@ -1,15 +1,13 @@
 package main
 
-//go:generate go run main.go
-
 import (
 	"fmt"
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	/*
 	   In this example we use a custom `ValueFormatter` for the y axis, letting us specify how to format text of the y-axis ticks.
 	   You can also do this for the x-axis, or the secondary y-axis.
@@ -18,6 +16,9 @@ func main() {
 
 	graph := chart.Chart{
 		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true,
+			},
 			ValueFormatter: func(v interface{}) string {
 				if vf, isFloat := v.(float64); isFloat {
 					return fmt.Sprintf("%0.6f", vf)
@@ -32,7 +33,12 @@ func main() {
 			},
 		},
 	}
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/custom_padding/main.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/drawing"
+)
+
+func drawChart(res http.ResponseWriter, req *http.Request) {
+	graph := chart.Chart{
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top:    50,
+				Left:   25,
+				Right:  25,
+				Bottom: 10,
+			},
+			FillColor: drawing.ColorFromHex("efefef"),
+		},
+		XAxis: chart.XAxis{
+			Style: chart.Style{
+				Show: true,
+			},
+		},
+		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true,
+			},
+		},
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: chart.Sequence.Float64(1.0, 100.0),
+				YValues: chart.Sequence.Random(100.0, 256.0),
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func drawChartDefault(res http.ResponseWriter, req *http.Request) {
+	graph := chart.Chart{
+		Background: chart.Style{
+			FillColor: drawing.ColorFromHex("efefef"),
+		},
+		XAxis: chart.XAxis{
+			Style: chart.Style{
+				Show: true,
+			},
+		},
+		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true,
+			},
+		},
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: chart.Sequence.Float64(1.0, 100.0),
+				YValues: chart.Sequence.Random(100.0, 256.0),
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.HandleFunc("/default", drawChartDefault)
+	http.ListenAndServe(":8080", nil)
+}

_examples/custom_ranges/main.go

@@ -1,14 +1,12 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	/*
 	   In this example we set a custom range for the y-axis, overriding the automatic range generation.
 	   Note: the chart will still generate the ticks automatically based on the custom range, so the intervals may be a bit weird.
@@ -16,6 +14,9 @@ func main() {
 
 	graph := chart.Chart{
 		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true,
+			},
 			Range: &chart.ContinuousRange{
 				Min: 0.0,
 				Max: 10.0,
@@ -28,7 +29,12 @@ func main() {
 			},
 		},
 	}
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/custom_styles/main.go

@@ -1,15 +1,13 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
-	"git.smarteching.com/zeni/go-chart/v2/drawing"
+	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/drawing"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	/*
 	   In this example we set some custom colors for the series and the chart background and canvas.
 	*/
@@ -23,6 +21,7 @@ func main() {
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
+					Show:        true,                           //note; if we set ANY other properties, we must set this to true.
 					StrokeColor: drawing.ColorRed,               // will supercede defaults
 					FillColor:   drawing.ColorRed.WithAlpha(64), // will supercede defaults
 				},
@@ -32,7 +31,11 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/custom_ticks/main.go

@@ -1,14 +1,12 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	/*
 	   In this example we set a custom set of ticks to use for the y-axis. It can be (almost) whatever you want, including some custom labels for ticks.
 	   Custom ticks will supercede a custom range, which will supercede automatic generation based on series values.
@@ -16,17 +14,20 @@ func main() {
 
 	graph := chart.Chart{
 		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true,
+			},
 			Range: &chart.ContinuousRange{
 				Min: 0.0,
 				Max: 4.0,
 			},
 			Ticks: []chart.Tick{
-				{Value: 0.0, Label: "0.00"},
-				{Value: 2.0, Label: "2.00"},
-				{Value: 4.0, Label: "4.00"},
-				{Value: 6.0, Label: "6.00"},
-				{Value: 8.0, Label: "Eight"},
-				{Value: 10.0, Label: "Ten"},
+				{0.0, "0.00"},
+				{2.0, "2.00"},
+				{4.0, "4.00"},
+				{6.0, "6.00"},
+				{8.0, "Eight"},
+				{10.0, "Ten"},
 			},
 		},
 		Series: []chart.Series{
@@ -36,7 +37,12 @@ func main() {
 			},
 		},
 	}
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/descending/main.go

@@ -1,14 +1,12 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 	   The below will draw the same chart as the `basic` example, except with both the x and y axes turned on.
@@ -21,12 +19,18 @@ func main() {
 	graph := chart.Chart{
 		Height: 500,
 		Width:  500,
-		XAxis:  chart.XAxis{
+		XAxis: chart.XAxis{
+			Style: chart.Style{
+				Show: true,
+			},
 			/*Range: &chart.ContinuousRange{
 				Descending: true,
 			},*/
 		},
 		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true,
+			},
 			Range: &chart.ContinuousRange{
 				Descending: true,
 			},
@@ -34,6 +38,7 @@ func main() {
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
+					Show:        true,
 					StrokeColor: chart.GetDefaultColor(0).WithAlpha(64),
 					FillColor:   chart.GetDefaultColor(0).WithAlpha(64),
 				},
@@ -43,7 +48,11 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/image_writer/main.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"log"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
 func main() {

_examples/legend/main.go

@@ -1,14 +1,12 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	chart "git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 	   In this example we add a `Renderable` or a custom component to the `Elements` array.
@@ -17,6 +15,12 @@ func main() {
 	*/
 
 	graph := chart.Chart{
+		XAxis: chart.XAxis{
+			Style: chart.Style{Show: true},
+		},
+		YAxis: chart.YAxis{
+			Style: chart.Style{Show: true},
+		},
 		Background: chart.Style{
 			Padding: chart.Box{
 				Top:  20,
@@ -37,7 +41,11 @@ func main() {
 		chart.Legend(&graph),
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/legend_left/main.go

@@ -1,14 +1,12 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 	   In this example we add a `Renderable` or a custom component to the `Elements` array.
@@ -17,6 +15,12 @@ func main() {
 	*/
 
 	graph := chart.Chart{
+		XAxis: chart.XAxis{
+			Style: chart.Style{Show: true},
+		},
+		YAxis: chart.YAxis{
+			Style: chart.Style{Show: true},
+		},
 		Background: chart.Style{
 			Padding: chart.Box{
 				Top:  20,
@@ -97,7 +101,11 @@ func main() {
 		chart.LegendLeft(&graph),
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/linear_regression/main.go

@@ -1,24 +1,22 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	chart "git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 		In this example we add a new type of series, a `SimpleMovingAverageSeries` that takes another series as a required argument.
-		InnerSeries only needs to implement `ValuesProvider`, so really you could chain `SimpleMovingAverageSeries` together if you wanted.
+		InnerSeries only needs to implement `ValueProvider`, so really you could chain `SimpleMovingAverageSeries` together if you wanted.
 	*/
 
 	mainSeries := chart.ContinuousSeries{
 		Name:    "A test series",
-		XValues: chart.Seq{Sequence: chart.NewLinearSequence().WithStart(1.0).WithEnd(100.0)}.Values(),        //generates a []float64 from 1.0 to 100.0 in 1.0 step increments, or 100 elements.
-		YValues: chart.Seq{Sequence: chart.NewRandomSequence().WithLen(100).WithMin(0).WithMax(100)}.Values(), //generates a []float64 randomly from 0 to 100 with 100 elements.
+		XValues: chart.Sequence.Float64(1.0, 100.0), //generates a []float64 from 1.0 to 100.0 in 1.0 step increments, or 100 elements.
+		YValues: chart.Sequence.Random(100, 100),    //generates a []float64 randomly from 0 to 100 with 100 elements.
 	}
 
 	// note we create a LinearRegressionSeries series by assignin the inner series.
@@ -34,7 +32,11 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/market_hours/main.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/wcharczuk/go-chart"
+)
+
+func drawChart(res http.ResponseWriter, req *http.Request) {
+	start := chart.Date.Date(2016, 7, 01, chart.Date.Eastern())
+	end := chart.Date.Date(2016, 07, 21, chart.Date.Eastern())
+	xv := chart.Sequence.MarketHours(start, end, chart.NYSEOpen, chart.NYSEClose, chart.Date.IsNYSEHoliday)
+	yv := chart.Sequence.RandomWithAverage(len(xv), 200, 10)
+
+	graph := chart.Chart{
+		XAxis: chart.XAxis{
+			Style:          chart.StyleShow(),
+			TickPosition:   chart.TickPositionBetweenTicks,
+			ValueFormatter: chart.TimeHourValueFormatter,
+			Range: &chart.MarketHoursRange{
+				MarketOpen:      chart.NYSEOpen,
+				MarketClose:     chart.NYSEClose,
+				HolidayProvider: chart.Date.IsNYSEHoliday,
+			},
+		},
+		YAxis: chart.YAxis{
+			Style: chart.StyleShow(),
+		},
+		Series: []chart.Series{
+			chart.TimeSeries{
+				XValues: xv,
+				YValues: yv,
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
+}

_examples/min_max/main.go

@@ -1,22 +1,21 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	mainSeries := chart.ContinuousSeries{
 		Name:    "A test series",
-		XValues: chart.Seq{Sequence: chart.NewLinearSequence().WithStart(1.0).WithEnd(100.0)}.Values(),
-		YValues: chart.Seq{Sequence: chart.NewRandomSequence().WithLen(100).WithMin(50).WithMax(150)}.Values(),
+		XValues: chart.Sequence.Float64(1.0, 100.0),
+		YValues: chart.Sequence.RandomWithAverage(100, 100, 50),
 	}
 
 	minSeries := &chart.MinSeries{
 		Style: chart.Style{
+			Show:            true,
 			StrokeColor:     chart.ColorAlternateGray,
 			StrokeDashArray: []float64{5.0, 5.0},
 		},
@@ -25,6 +24,7 @@ func main() {
 
 	maxSeries := &chart.MaxSeries{
 		Style: chart.Style{
+			Show:            true,
 			StrokeColor:     chart.ColorAlternateGray,
 			StrokeDashArray: []float64{5.0, 5.0},
 		},
@@ -35,27 +35,35 @@ func main() {
 		Width:  1920,
 		Height: 1080,
 		YAxis: chart.YAxis{
-			Name: "Random Values",
+			Name:      "Random Values",
+			NameStyle: chart.StyleShow(),
+			Style:     chart.StyleShow(),
 			Range: &chart.ContinuousRange{
 				Min: 25,
 				Max: 175,
 			},
 		},
 		XAxis: chart.XAxis{
-			Name: "Random Other Values",
+			Name:      "Random Other Values",
+			NameStyle: chart.StyleShow(),
+			Style:     chart.StyleShow(),
 		},
 		Series: []chart.Series{
 			mainSeries,
 			minSeries,
 			maxSeries,
-			chart.LastValueAnnotationSeries(minSeries),
-			chart.LastValueAnnotationSeries(maxSeries),
+			chart.LastValueAnnotation(minSeries),
+			chart.LastValueAnnotation(maxSeries),
 		},
 	}
 
 	graph.Elements = []chart.Renderable{chart.Legend(&graph)}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/pie_chart/main.go

@@ -5,7 +5,7 @@ import (
 	"log"
 	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
@@ -30,26 +30,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 	}
 }
 
-func drawChartRegression(res http.ResponseWriter, req *http.Request) {
-	pie := chart.PieChart{
-		Width:  512,
-		Height: 512,
-		Values: []chart.Value{
-			{Value: 5, Label: "Blue"},
-			{Value: 2, Label: "Two"},
-			{Value: 1, Label: "One"},
-		},
-	}
-
-	res.Header().Set("Content-Type", chart.ContentTypeSVG)
-	err := pie.Render(chart.SVG, res)
-	if err != nil {
-		fmt.Printf("Error rendering pie chart: %v\n", err)
-	}
-}
-
 func main() {
 	http.HandleFunc("/", drawChart)
-	http.HandleFunc("/reg", drawChartRegression)
 	log.Fatal(http.ListenAndServe(":8080", nil))
 }

_examples/request_timings/main.go

@@ -0,0 +1,135 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/wcharczuk/go-chart"
+)
+
+func parseInt(str string) int {
+	v, _ := strconv.Atoi(str)
+	return v
+}
+
+func parseFloat64(str string) float64 {
+	v, _ := strconv.ParseFloat(str, 64)
+	return v
+}
+
+func readData() ([]time.Time, []float64) {
+	var xvalues []time.Time
+	var yvalues []float64
+	err := chart.File.ReadByLines("requests.csv", func(line string) {
+		parts := strings.Split(line, ",")
+		year := parseInt(parts[0])
+		month := parseInt(parts[1])
+		day := parseInt(parts[2])
+		hour := parseInt(parts[3])
+		elapsedMillis := parseFloat64(parts[4])
+		xvalues = append(xvalues, time.Date(year, time.Month(month), day, hour, 0, 0, 0, time.UTC))
+		yvalues = append(yvalues, elapsedMillis)
+	})
+	if err != nil {
+		fmt.Println(err.Error())
+	}
+	return xvalues, yvalues
+}
+
+func releases() []chart.GridLine {
+	return []chart.GridLine{
+		{Value: chart.Time.ToFloat64(time.Date(2016, 8, 1, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.Time.ToFloat64(time.Date(2016, 8, 2, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.Time.ToFloat64(time.Date(2016, 8, 2, 15, 30, 0, 0, time.UTC))},
+		{Value: chart.Time.ToFloat64(time.Date(2016, 8, 4, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.Time.ToFloat64(time.Date(2016, 8, 5, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.Time.ToFloat64(time.Date(2016, 8, 6, 9, 30, 0, 0, time.UTC))},
+	}
+}
+
+func drawChart(res http.ResponseWriter, req *http.Request) {
+	xvalues, yvalues := readData()
+	mainSeries := chart.TimeSeries{
+		Name: "Prod Request Timings",
+		Style: chart.Style{
+			Show:        true,
+			StrokeColor: chart.ColorBlue,
+			FillColor:   chart.ColorBlue.WithAlpha(100),
+		},
+		XValues: xvalues,
+		YValues: yvalues,
+	}
+
+	linreg := &chart.LinearRegressionSeries{
+		Name: "Linear Regression",
+		Style: chart.Style{
+			Show:            true,
+			StrokeColor:     chart.ColorAlternateBlue,
+			StrokeDashArray: []float64{5.0, 5.0},
+		},
+		InnerSeries: mainSeries,
+	}
+
+	sma := &chart.SMASeries{
+		Name: "SMA",
+		Style: chart.Style{
+			Show:            true,
+			StrokeColor:     chart.ColorRed,
+			StrokeDashArray: []float64{5.0, 5.0},
+		},
+		InnerSeries: mainSeries,
+	}
+
+	graph := chart.Chart{
+		Width:  1280,
+		Height: 720,
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top: 50,
+			},
+		},
+		YAxis: chart.YAxis{
+			Name:      "Elapsed Millis",
+			NameStyle: chart.StyleShow(),
+			Style:     chart.StyleShow(),
+			TickStyle: chart.Style{
+				TextRotationDegrees: 45.0,
+			},
+			ValueFormatter: func(v interface{}) string {
+				return fmt.Sprintf("%d ms", int(v.(float64)))
+			},
+		},
+		XAxis: chart.XAxis{
+			Style: chart.Style{
+				Show: true,
+			},
+			ValueFormatter: chart.TimeHourValueFormatter,
+			GridMajorStyle: chart.Style{
+				Show:        true,
+				StrokeColor: chart.ColorAlternateGray,
+				StrokeWidth: 1.0,
+			},
+			GridLines: releases(),
+		},
+		Series: []chart.Series{
+			mainSeries,
+			linreg,
+			chart.LastValueAnnotation(linreg),
+			sma,
+			chart.LastValueAnnotation(sma),
+		},
+	}
+
+	graph.Elements = []chart.Renderable{chart.LegendThin(&graph)}
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
+}

_examples/scatter/main.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/wcharczuk/go-chart"
+)
+
+func drawChart(res http.ResponseWriter, req *http.Request) {
+	graph := chart.Chart{
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				Style: chart.Style{
+					Show:        true,
+					StrokeWidth: chart.Disabled,
+					DotWidth:    3,
+				},
+				XValues: chart.Sequence.Random(32, 1024),
+				YValues: chart.Sequence.Random(32, 1024),
+			},
+			chart.ContinuousSeries{
+				Style: chart.Style{
+					Show:        true,
+					StrokeWidth: chart.Disabled,
+					DotWidth:    5,
+				},
+				XValues: chart.Sequence.Random(16, 1024),
+				YValues: chart.Sequence.Random(16, 1024),
+			},
+			chart.ContinuousSeries{
+				Style: chart.Style{
+					Show:        true,
+					StrokeWidth: chart.Disabled,
+					DotWidth:    7,
+				},
+				XValues: chart.Sequence.Random(8, 1024),
+				YValues: chart.Sequence.Random(8, 1024),
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	err := graph.Render(chart.PNG, res)
+	if err != nil {
+		log.Println(err.Error())
+	}
+
+}
+
+func unit(res http.ResponseWriter, req *http.Request) {
+	graph := chart.Chart{
+		Height: 50,
+		Width:  50,
+		Canvas: chart.Style{
+			Padding: chart.Box{IsSet: true},
+		},
+		Background: chart.Style{
+			Padding: chart.Box{IsSet: true},
+		},
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: chart.Sequence.Float64(0, 4, 1),
+				YValues: chart.Sequence.Float64(0, 4, 1),
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	err := graph.Render(chart.PNG, res)
+	if err != nil {
+		log.Println(err.Error())
+	}
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.HandleFunc("/unit", unit)
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}

_examples/simple_moving_average/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/wcharczuk/go-chart"
+)
+
+func drawChart(res http.ResponseWriter, req *http.Request) {
+
+	/*
+		In this example we add a new type of series, a `SimpleMovingAverageSeries` that takes another series as a required argument.
+		InnerSeries only needs to implement `ValueProvider`, so really you could chain `SimpleMovingAverageSeries` together if you wanted.
+	*/
+
+	mainSeries := chart.ContinuousSeries{
+		Name:    "A test series",
+		XValues: chart.Sequence.Float64(1.0, 100.0), //generates a []float64 from 1.0 to 100.0 in 1.0 step increments, or 100 elements.
+		YValues: chart.Sequence.Random(100, 100),    //generates a []float64 randomly from 0 to 100 with 100 elements.
+	}
+
+	// note we create a SimpleMovingAverage series by assignin the inner series.
+	// we need to use a reference because `.Render()` needs to modify state within the series.
+	smaSeries := &chart.SMASeries{
+		InnerSeries: mainSeries,
+	} // we can optionally set the `WindowSize` property which alters how the moving average is calculated.
+
+	graph := chart.Chart{
+		Series: []chart.Series{
+			mainSeries,
+			smaSeries,
+		},
+	}
+
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
+}

_examples/stacked_bar/main.go

@@ -1,20 +1,22 @@
 package main
 
 import (
-	"os"
+	"fmt"
+	"log"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	sbc := chart.StackedBarChart{
-		Title: "Test Stacked Bar Chart",
-		Background: chart.Style{
-			Padding: chart.Box{
-				Top: 40,
-			},
-		},
 		Height: 512,
+		XAxis: chart.Style{
+			Show: true,
+		},
+		YAxis: chart.Style{
+			Show: true,
+		},
 		Bars: []chart.StackedBar{
 			{
 				Name: "This is a very long string to test word break wrapping.",
@@ -47,7 +49,14 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	sbc.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	err := sbc.Render(chart.PNG, res)
+	if err != nil {
+		fmt.Printf("Error rendering chart: %v\n", err)
+	}
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	log.Fatal(http.ListenAndServe(":8080", nil))
 }

_examples/stock_analysis/main.go

@@ -1,21 +1,20 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 	"time"
 
-	"git.smarteching.com/zeni/go-chart/v2"
-	"git.smarteching.com/zeni/go-chart/v2/drawing"
+	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/drawing"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	xv, yv := xvalues(), yvalues()
 
 	priceSeries := chart.TimeSeries{
 		Name: "SPY",
 		Style: chart.Style{
+			Show:        true,
 			StrokeColor: chart.GetDefaultColor(0),
 		},
 		XValues: xv,
@@ -25,6 +24,7 @@ func main() {
 	smaSeries := chart.SMASeries{
 		Name: "SPY - SMA",
 		Style: chart.Style{
+			Show:            true,
 			StrokeColor:     drawing.ColorRed,
 			StrokeDashArray: []float64{5.0, 5.0},
 		},
@@ -34,6 +34,7 @@ func main() {
 	bbSeries := &chart.BollingerBandsSeries{
 		Name: "SPY - Bol. Bands",
 		Style: chart.Style{
+			Show:        true,
 			StrokeColor: drawing.ColorFromHex("efefef"),
 			FillColor:   drawing.ColorFromHex("efefef").WithAlpha(64),
 		},
@@ -42,9 +43,11 @@ func main() {
 
 	graph := chart.Chart{
 		XAxis: chart.XAxis{
+			Style:        chart.Style{Show: true},
 			TickPosition: chart.TickPositionBetweenTicks,
 		},
 		YAxis: chart.YAxis{
+			Style: chart.Style{Show: true},
 			Range: &chart.ContinuousRange{
 				Max: 220.0,
 				Min: 180.0,
@@ -57,9 +60,8 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
 }
 
 func xvalues() []time.Time {
@@ -76,3 +78,8 @@ func xvalues() []time.Time {
 func yvalues() []float64 {
 	return []float64{212.47, 212.59, 211.76, 211.37, 210.18, 208.00, 206.79, 209.33, 210.77, 210.82, 210.50, 209.79, 209.38, 210.07, 208.35, 207.95, 210.57, 208.66, 208.92, 208.66, 209.42, 210.59, 209.98, 208.32, 203.97, 197.83, 189.50, 187.27, 194.46, 199.27, 199.28, 197.67, 191.77, 195.41, 195.55, 192.59, 197.43, 194.79, 195.85, 196.74, 196.01, 198.45, 200.18, 199.73, 195.45, 196.46, 193.90, 193.60, 192.90, 192.87, 188.01, 188.12, 191.63, 192.13, 195.00, 198.47, 197.79, 199.41, 201.21, 201.33, 201.52, 200.25, 199.29, 202.35, 203.27, 203.37, 203.11, 201.85, 205.26, 207.51, 207.00, 206.60, 208.95, 208.83, 207.93, 210.39, 211.00, 210.36, 210.15, 210.04, 208.08, 208.56, 207.74, 204.84, 202.54, 205.62, 205.47, 208.73, 208.55, 209.31, 209.07, 209.35, 209.32, 209.56, 208.69, 210.68, 208.53, 205.61, 209.62, 208.35, 206.95, 205.34, 205.87, 201.88, 202.90, 205.03, 208.03, 204.86, 200.02, 201.67, 203.50, 206.02, 205.68, 205.21, 207.40, 205.93, 203.87, 201.02, 201.36, 198.82, 194.05, 191.92, 192.11, 193.66, 188.83, 191.93, 187.81, 188.06, 185.65, 186.69, 190.52, 187.64, 190.20, 188.13, 189.11, 193.72, 193.65, 190.16, 191.30, 191.60, 187.95, 185.42, 185.43, 185.27, 182.86, 186.63, 189.78, 192.88, 192.09, 192.00, 194.78, 192.32, 193.20, 195.54, 195.09, 193.56, 198.11, 199.00, 199.78, 200.43, 200.59, 198.40, 199.38, 199.54, 202.76, 202.50, 202.17, 203.34, 204.63, 204.38, 204.67, 204.56, 203.21, 203.12, 203.24, 205.12, 206.02, 205.52, 206.92, 206.25, 204.19, 206.42, 203.95, 204.50, 204.02, 205.92, 208.00, 208.01, 207.78, 209.24, 209.90, 210.10, 208.97, 208.97, 208.61, 208.92, 209.35, 207.45, 206.33, 207.97, 206.16, 205.01, 204.97, 205.72, 205.89, 208.45, 206.50, 206.56, 204.76, 206.78, 204.85, 204.91, 204.20, 205.49, 205.21, 207.87, 209.28, 209.34, 210.24, 209.84, 210.27, 210.91, 210.28, 211.35, 211.68, 212.37, 212.08, 210.07, 208.45, 208.04, 207.75, 208.37, 206.52, 207.85, 208.44, 208.10, 210.81, 203.24, 199.60, 203.20, 206.66, 209.48, 209.92, 208.41, 209.66, 209.53, 212.65, 213.40, 214.95, 214.92, 216.12, 215.83}
 }
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
+}

_examples/text_rotation/main.go

@@ -1,15 +1,13 @@
 package main
 
-//go:generate go run main.go
-
 import (
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
-	"git.smarteching.com/zeni/go-chart/v2/drawing"
+	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/drawing"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 	f, _ := chart.GetDefaultFont()
 	r, _ := chart.PNG(1024, 1024)
 
@@ -45,7 +43,11 @@ func main() {
 		StrokeWidth: 2,
 	})
 
-	file, _ := os.Create("output.png")
-	defer file.Close()
-	r.Save(file)
+	res.Header().Set("Content-Type", "image/png")
+	r.Save(res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/timeseries/main.go

@@ -4,15 +4,20 @@ import (
 	"net/http"
 	"time"
 
-	chart "git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
 	/*
 	   This is an example of using the `TimeSeries` to automatically coerce time.Time values into a continuous xrange.
-	   Note: chart.TimeSeries implements `ValueFormatterProvider` and as a result gives the XAxis the appropriate formatter to use for the ticks.
+	   Note: chart.TimeSeries implements `ValueFormatterProvider` and as a result gives the XAxis the appropariate formatter to use for the ticks.
 	*/
 	graph := chart.Chart{
+		XAxis: chart.XAxis{
+			Style: chart.Style{
+				Show: true,
+			},
+		},
 		Series: []chart.Series{
 			chart.TimeSeries{
 				XValues: []time.Time{
@@ -43,6 +48,9 @@ func drawCustomChart(res http.ResponseWriter, req *http.Request) {
 	*/
 	graph := chart.Chart{
 		XAxis: chart.XAxis{
+			Style: chart.Style{
+				Show: true,
+			},
 			ValueFormatter: chart.TimeHourValueFormatter,
 		},
 		Series: []chart.Series{
@@ -71,7 +79,7 @@ func drawCustomChart(res http.ResponseWriter, req *http.Request) {
 
 func main() {
 	http.HandleFunc("/", drawChart)
-	http.HandleFunc("/favicon.ico", func(res http.ResponseWriter, req *http.Request) {
+	http.HandleFunc("/favico.ico", func(res http.ResponseWriter, req *http.Request) {
 		res.Write([]byte{})
 	})
 	http.HandleFunc("/custom", drawCustomChart)

_examples/twoaxis/main.go

@@ -1,15 +1,13 @@
 package main
 
-//go:generate go run main.go
-
 import (
 	"fmt"
-	"os"
+	"net/http"
 
-	"git.smarteching.com/zeni/go-chart/v2"
+	"github.com/wcharczuk/go-chart"
 )
 
-func main() {
+func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 	   In this example we add a second series, and assign it to the secondary y axis, giving that series it's own range.
@@ -19,13 +17,26 @@ func main() {
 
 	graph := chart.Chart{
 		XAxis: chart.XAxis{
+			Style: chart.Style{
+				Show: true, //enables / displays the x-axis
+			},
 			TickPosition: chart.TickPositionBetweenTicks,
 			ValueFormatter: func(v interface{}) string {
 				typed := v.(float64)
-				typedDate := chart.TimeFromFloat64(typed)
+				typedDate := chart.Time.FromFloat64(typed)
 				return fmt.Sprintf("%d-%d\n%d", typedDate.Month(), typedDate.Day(), typedDate.Year())
 			},
 		},
+		YAxis: chart.YAxis{
+			Style: chart.Style{
+				Show: true, //enables / displays the y-axis
+			},
+		},
+		YAxisSecondary: chart.YAxis{
+			Style: chart.Style{
+				Show: true, //enables / displays the secondary y-axis
+			},
+		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				XValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
@@ -39,7 +50,11 @@ func main() {
 		},
 	}
 
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
+	res.Header().Set("Content-Type", "image/png")
+	graph.Render(chart.PNG, res)
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.ListenAndServe(":8080", nil)
 }

_examples/twopoint/main.go

@@ -1,27 +1,32 @@
 package main
 
-//go:generate go run main.go
-
 import (
 	"bytes"
 	"log"
 	"os"
-
-	"git.smarteching.com/zeni/go-chart/v2"
+	//"time"
+	"github.com/wcharczuk/go-chart" //exposes "chart"
 )
 
 func main() {
+
 	var b float64
 	b = 1000
 
 	ts1 := chart.ContinuousSeries{ //TimeSeries{
-		Name:    "Time Series",
+		Name: "Time Series",
+		Style: chart.Style{
+			Show: true,
+		},
+
+		//XValues: []time.Time{time.Unix(3*b,0),time.Unix(4*b,0),time.Unix(5*b,0),time.Unix(6*b,0),time.Unix(7*b,0),time.Unix(8*b,0),time.Unix(9*b,0),time.Unix(10*b,0)},
 		XValues: []float64{10 * b, 20 * b, 30 * b, 40 * b, 50 * b, 60 * b, 70 * b, 80 * b},
 		YValues: []float64{1.0, 2.0, 30.0, 4.0, 50.0, 6.0, 7.0, 88.0},
 	}
 
 	ts2 := chart.ContinuousSeries{ //TimeSeries{
 		Style: chart.Style{
+			Show:        true,
 			StrokeColor: chart.GetDefaultColor(1),
 		},
 
@@ -33,11 +38,15 @@ func main() {
 
 		XAxis: chart.XAxis{
 			Name:           "The XAxis",
+			NameStyle:      chart.StyleShow(),
+			Style:          chart.StyleShow(),
 			ValueFormatter: chart.TimeMinuteValueFormatter, //TimeHourValueFormatter,
 		},
 
 		YAxis: chart.YAxis{
-			Name: "The YAxis",
+			Name:      "The YAxis",
+			NameStyle: chart.StyleShow(),
+			Style:     chart.StyleShow(),
 		},
 
 		Series: []chart.Series{

annotation_series.go

@@ -5,11 +5,6 @@ import (
 	"math"
 )
 
-// Interface Assertions.
-var (
-	_ Series = (*AnnotationSeries)(nil)
-)
-
 // AnnotationSeries is a series of labels on the chart.
 type AnnotationSeries struct {
 	Name        string
@@ -53,17 +48,17 @@ func (as AnnotationSeries) Measure(r Renderer, canvasBox Box, xrange, yrange Ran
 		Right:  0,
 		Bottom: 0,
 	}
-	if !as.Style.Hidden {
+	if as.Style.IsZero() || as.Style.Show {
 		seriesStyle := as.Style.InheritFrom(as.annotationStyleDefaults(defaults))
 		for _, a := range as.Annotations {
 			style := a.Style.InheritFrom(seriesStyle)
 			lx := canvasBox.Left + xrange.Translate(a.XValue)
 			ly := canvasBox.Bottom - yrange.Translate(a.YValue)
 			ab := Draw.MeasureAnnotation(r, canvasBox, style, lx, ly, a.Label)
-			box.Top = MinInt(box.Top, ab.Top)
-			box.Left = MinInt(box.Left, ab.Left)
-			box.Right = MaxInt(box.Right, ab.Right)
-			box.Bottom = MaxInt(box.Bottom, ab.Bottom)
+			box.Top = Math.MinInt(box.Top, ab.Top)
+			box.Left = Math.MinInt(box.Left, ab.Left)
+			box.Right = Math.MaxInt(box.Right, ab.Right)
+			box.Bottom = Math.MaxInt(box.Bottom, ab.Bottom)
 		}
 	}
 	return box
@@ -71,7 +66,7 @@ func (as AnnotationSeries) Measure(r Renderer, canvasBox Box, xrange, yrange Ran
 
 // Render draws the series.
 func (as AnnotationSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
-	if !as.Style.Hidden {
+	if as.Style.IsZero() || as.Style.Show {
 		seriesStyle := as.Style.InheritFrom(as.annotationStyleDefaults(defaults))
 		for _, a := range as.Annotations {
 			style := a.Style.InheritFrom(seriesStyle)

annotation_series_test.go

@@ -4,14 +4,17 @@ import (
 	"image/color"
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/drawing"
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	"github.com/blendlabs/go-assert"
+	"github.com/wcharczuk/go-chart/drawing"
 )
 
 func TestAnnotationSeriesMeasure(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	as := AnnotationSeries{
+		Style: Style{
+			Show: true,
+		},
 		Annotations: []Value2{
 			{XValue: 1.0, YValue: 1.0, Label: "1.0"},
 			{XValue: 2.0, YValue: 2.0, Label: "2.0"},
@@ -21,10 +24,10 @@ func TestAnnotationSeriesMeasure(t *testing.T) {
 	}
 
 	r, err := PNG(110, 110)
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 
 	f, err := GetDefaultFont()
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 
 	xrange := &ContinuousRange{
 		Min:    1.0,
@@ -49,18 +52,19 @@ func TestAnnotationSeriesMeasure(t *testing.T) {
 	}
 
 	box := as.Measure(r, cb, xrange, yrange, sd)
-	testutil.AssertFalse(t, box.IsZero())
-	testutil.AssertEqual(t, -5.0, box.Top)
-	testutil.AssertEqual(t, 5.0, box.Left)
-	testutil.AssertEqual(t, 146.0, box.Right) //the top,left annotation sticks up 5px and out ~44px.
-	testutil.AssertEqual(t, 115.0, box.Bottom)
+	assert.False(box.IsZero())
+	assert.Equal(-5.0, box.Top)
+	assert.Equal(5.0, box.Left)
+	assert.Equal(146.0, box.Right) //the top,left annotation sticks up 5px and out ~44px.
+	assert.Equal(115.0, box.Bottom)
 }
 
 func TestAnnotationSeriesRender(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	as := AnnotationSeries{
 		Style: Style{
+			Show:        true,
 			FillColor:   drawing.ColorWhite,
 			StrokeColor: drawing.ColorBlack,
 		},
@@ -73,10 +77,10 @@ func TestAnnotationSeriesRender(t *testing.T) {
 	}
 
 	r, err := PNG(110, 110)
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 
 	f, err := GetDefaultFont()
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 
 	xrange := &ContinuousRange{
 		Min:    1.0,
@@ -103,13 +107,13 @@ func TestAnnotationSeriesRender(t *testing.T) {
 	as.Render(r, cb, xrange, yrange, sd)
 
 	rr, isRaster := r.(*rasterRenderer)
-	testutil.AssertTrue(t, isRaster)
-	testutil.AssertNotNil(t, rr)
+	assert.True(isRaster)
+	assert.NotNil(rr)
 
 	c := rr.i.At(38, 70)
 	converted, isRGBA := color.RGBAModel.Convert(c).(color.RGBA)
-	testutil.AssertTrue(t, isRGBA)
-	testutil.AssertEqual(t, 0, converted.R)
-	testutil.AssertEqual(t, 0, converted.G)
-	testutil.AssertEqual(t, 0, converted.B)
+	assert.True(isRGBA)
+	assert.Equal(0, converted.R)
+	assert.Equal(0, converted.G)
+	assert.Equal(0, converted.B)
 }

array.go

@@ -1,24 +0,0 @@
-package chart
-
-var (
-	_ Sequence = (*Array)(nil)
-)
-
-// NewArray returns a new array from a given set of values.
-// Array implements Sequence, which allows it to be used with the sequence helpers.
-func NewArray(values ...float64) Array {
-	return Array(values)
-}
-
-// Array is a wrapper for an array of floats that implements `ValuesProvider`.
-type Array []float64
-
-// Len returns the value provider length.
-func (a Array) Len() int {
-	return len(a)
-}
-
-// GetValue returns the value at a given index.
-func (a Array) GetValue(index int) float64 {
-	return a[index]
-}

bar_chart.go

@@ -14,8 +14,6 @@ type BarChart struct {
 	Title      string
 	TitleStyle Style
 
-	ColorPalette ColorPalette
-
 	Width  int
 	Height int
 	DPI    float64
@@ -30,9 +28,6 @@ type BarChart struct {
 
 	BarSpacing int
 
-	UseBaseValue bool
-	BaseValue    float64
-
 	Font        *truetype.Font
 	defaultFont *truetype.Font
 
@@ -128,7 +123,7 @@ func (bc BarChart) Render(rp RendererProvider, w io.Writer) error {
 		canvasBox = bc.getAdjustedCanvasBox(r, canvasBox, yr, yt)
 		yr = bc.setRangeDomains(canvasBox, yr)
 	}
-	bc.drawCanvas(r, canvasBox)
+
 	bc.drawBars(r, canvasBox, yr)
 	bc.drawXAxis(r, canvasBox)
 	bc.drawYAxis(r, canvasBox, yr, yt)
@@ -141,10 +136,6 @@ func (bc BarChart) Render(rp RendererProvider, w io.Writer) error {
 	return r.Save(w)
 }
 
-func (bc BarChart) drawCanvas(r Renderer, canvasBox Box) {
-	Draw.Box(r, canvasBox, bc.getCanvasStyle())
-}
-
 func (bc BarChart) getRanges() Range {
 	var yrange Range
 	if bc.YAxis.Range != nil && !bc.YAxis.Range.IsZero() {
@@ -201,20 +192,11 @@ func (bc BarChart) drawBars(r Renderer, canvasBox Box, yr Range) {
 
 		by = canvasBox.Bottom - yr.Translate(bar.Value)
 
-		if bc.UseBaseValue {
-			barBox = Box{
-				Top:    by,
-				Left:   bxl,
-				Right:  bxr,
-				Bottom: canvasBox.Bottom - yr.Translate(bc.BaseValue),
-			}
-		} else {
-			barBox = Box{
-				Top:    by,
-				Left:   bxl,
-				Right:  bxr,
-				Bottom: canvasBox.Bottom,
-			}
+		barBox = Box{
+			Top:    by,
+			Left:   bxl,
+			Right:  bxr,
+			Bottom: canvasBox.Bottom,
 		}
 
 		Draw.Box(r, barBox, bar.Style.InheritFrom(bc.styleDefaultsBar(index)))
@@ -224,7 +206,7 @@ func (bc BarChart) drawBars(r Renderer, canvasBox Box, yr Range) {
 }
 
 func (bc BarChart) drawXAxis(r Renderer, canvasBox Box) {
-	if !bc.XAxis.Hidden {
+	if bc.XAxis.Show {
 		axisStyle := bc.XAxis.InheritFrom(bc.styleDefaultsAxes())
 		axisStyle.WriteToRenderer(r)
 
@@ -263,44 +245,44 @@ func (bc BarChart) drawXAxis(r Renderer, canvasBox Box) {
 }
 
 func (bc BarChart) drawYAxis(r Renderer, canvasBox Box, yr Range, ticks []Tick) {
-	if !bc.YAxis.Style.Hidden {
-		bc.YAxis.Render(r, canvasBox, yr, bc.styleDefaultsAxes(), ticks)
+	if bc.YAxis.Style.Show {
+		axisStyle := bc.YAxis.Style.InheritFrom(bc.styleDefaultsAxes())
+		axisStyle.WriteToRenderer(r)
+
+		r.MoveTo(canvasBox.Right, canvasBox.Top)
+		r.LineTo(canvasBox.Right, canvasBox.Bottom)
+		r.Stroke()
+
+		r.MoveTo(canvasBox.Right, canvasBox.Bottom)
+		r.LineTo(canvasBox.Right+DefaultHorizontalTickWidth, canvasBox.Bottom)
+		r.Stroke()
+
+		var ty int
+		var tb Box
+		for _, t := range ticks {
+			ty = canvasBox.Bottom - yr.Translate(t.Value)
+
+			axisStyle.GetStrokeOptions().WriteToRenderer(r)
+			r.MoveTo(canvasBox.Right, ty)
+			r.LineTo(canvasBox.Right+DefaultHorizontalTickWidth, ty)
+			r.Stroke()
+
+			axisStyle.GetTextOptions().WriteToRenderer(r)
+			tb = r.MeasureText(t.Label)
+			Draw.Text(r, t.Label, canvasBox.Right+DefaultYAxisMargin+5, ty+(tb.Height()>>1), axisStyle)
+		}
+
 	}
 }
 
 func (bc BarChart) drawTitle(r Renderer) {
-	if len(bc.Title) > 0 && !bc.TitleStyle.Hidden {
-		r.SetFont(bc.TitleStyle.GetFont(bc.GetFont()))
-		r.SetFontColor(bc.TitleStyle.GetFontColor(bc.GetColorPalette().TextColor()))
-		titleFontSize := bc.TitleStyle.GetFontSize(bc.getTitleFontSize())
-		r.SetFontSize(titleFontSize)
-
-		textBox := r.MeasureText(bc.Title)
-
-		textWidth := textBox.Width()
-		textHeight := textBox.Height()
-
-		titleX := (bc.GetWidth() >> 1) - (textWidth >> 1)
-		titleY := bc.TitleStyle.Padding.GetTop(DefaultTitleTop) + textHeight
-
-		r.Text(bc.Title, titleX, titleY)
-	}
-}
-
-func (bc BarChart) getCanvasStyle() Style {
-	return bc.Canvas.InheritFrom(bc.styleDefaultsCanvas())
-}
-
-func (bc BarChart) styleDefaultsCanvas() Style {
-	return Style{
-		FillColor:   bc.GetColorPalette().CanvasColor(),
-		StrokeColor: bc.GetColorPalette().CanvasStrokeColor(),
-		StrokeWidth: DefaultCanvasStrokeWidth,
+	if len(bc.Title) > 0 && bc.TitleStyle.Show {
+		Draw.TextWithin(r, bc.Title, bc.box(), bc.styleDefaultsTitle())
 	}
 }
 
 func (bc BarChart) hasAxes() bool {
-	return !bc.YAxis.Style.Hidden
+	return bc.YAxis.Style.Show
 }
 
 func (bc BarChart) setRangeDomains(canvasBox Box, yr Range) Range {
@@ -320,7 +302,7 @@ func (bc BarChart) getValueFormatters() ValueFormatter {
 }
 
 func (bc BarChart) getAxesTicks(r Renderer, yr Range, yf ValueFormatter) (yticks []Tick) {
-	if !bc.YAxis.Style.Hidden {
+	if bc.YAxis.Style.Show {
 		yticks = bc.YAxis.GetTicks(r, yr, bc.styleDefaultsAxes(), yf)
 	}
 	return
@@ -366,7 +348,7 @@ func (bc BarChart) getAdjustedCanvasBox(r Renderer, canvasBox Box, yrange Range,
 
 	_, _, totalWidth := bc.calculateScaledTotalWidth(canvasBox)
 
-	if !bc.XAxis.Hidden {
+	if bc.XAxis.Show {
 		xaxisHeight := DefaultVerticalTickHeight
 
 		axisStyle := bc.XAxis.InheritFrom(bc.styleDefaultsAxes())
@@ -384,7 +366,7 @@ func (bc BarChart) getAdjustedCanvasBox(r Renderer, canvasBox Box, yrange Range,
 				lines := Text.WrapFit(r, bar.Label, barLabelBox.Width(), axisStyle)
 				linesBox := Text.MeasureLines(r, lines, axisStyle)
 
-				xaxisHeight = MinInt(linesBox.Height()+(2*DefaultXAxisMargin), xaxisHeight)
+				xaxisHeight = Math.MinInt(linesBox.Height()+(2*DefaultXAxisMargin), xaxisHeight)
 			}
 		}
 
@@ -398,7 +380,7 @@ func (bc BarChart) getAdjustedCanvasBox(r Renderer, canvasBox Box, yrange Range,
 		axesOuterBox = axesOuterBox.Grow(xbox)
 	}
 
-	if !bc.YAxis.Style.Hidden {
+	if bc.YAxis.Style.Show {
 		axesBounds := bc.YAxis.Measure(r, canvasBox, yrange, bc.styleDefaultsAxes(), yticks)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
@@ -412,8 +394,8 @@ func (bc BarChart) box() Box {
 	dpb := bc.Background.Padding.GetBottom(50)
 
 	return Box{
-		Top:    bc.Background.Padding.GetTop(20),
-		Left:   bc.Background.Padding.GetLeft(20),
+		Top:    20,
+		Left:   20,
 		Right:  bc.GetWidth() - dpr,
 		Bottom: bc.GetHeight() - dpb,
 	}
@@ -425,23 +407,23 @@ func (bc BarChart) getBackgroundStyle() Style {
 
 func (bc BarChart) styleDefaultsBackground() Style {
 	return Style{
-		FillColor:   bc.GetColorPalette().BackgroundColor(),
-		StrokeColor: bc.GetColorPalette().BackgroundStrokeColor(),
+		FillColor:   DefaultBackgroundColor,
+		StrokeColor: DefaultBackgroundStrokeColor,
 		StrokeWidth: DefaultStrokeWidth,
 	}
 }
 
 func (bc BarChart) styleDefaultsBar(index int) Style {
 	return Style{
-		StrokeColor: bc.GetColorPalette().GetSeriesColor(index),
+		StrokeColor: GetAlternateColor(index),
 		StrokeWidth: 3.0,
-		FillColor:   bc.GetColorPalette().GetSeriesColor(index),
+		FillColor:   GetAlternateColor(index),
 	}
 }
 
 func (bc BarChart) styleDefaultsTitle() Style {
 	return bc.TitleStyle.InheritFrom(Style{
-		FontColor:           bc.GetColorPalette().TextColor(),
+		FontColor:           DefaultTextColor,
 		Font:                bc.GetFont(),
 		FontSize:            bc.getTitleFontSize(),
 		TextHorizontalAlign: TextHorizontalAlignCenter,
@@ -451,7 +433,7 @@ func (bc BarChart) styleDefaultsTitle() Style {
 }
 
 func (bc BarChart) getTitleFontSize() float64 {
-	effectiveDimension := MinInt(bc.GetWidth(), bc.GetHeight())
+	effectiveDimension := Math.MinInt(bc.GetWidth(), bc.GetHeight())
 	if effectiveDimension >= 2048 {
 		return 48
 	} else if effectiveDimension >= 1024 {
@@ -466,10 +448,10 @@ func (bc BarChart) getTitleFontSize() float64 {
 
 func (bc BarChart) styleDefaultsAxes() Style {
 	return Style{
-		StrokeColor:         bc.GetColorPalette().AxisStrokeColor(),
+		StrokeColor:         DefaultAxisColor,
 		Font:                bc.GetFont(),
 		FontSize:            DefaultAxisFontSize,
-		FontColor:           bc.GetColorPalette().TextColor(),
+		FontColor:           DefaultAxisColor,
 		TextHorizontalAlign: TextHorizontalAlignCenter,
 		TextVerticalAlign:   TextVerticalAlignTop,
 		TextWrap:            TextWrapWord,
@@ -481,11 +463,3 @@ func (bc BarChart) styleDefaultsElements() Style {
 		Font: bc.GetFont(),
 	}
 }
-
-// GetColorPalette returns the color palette for the chart.
-func (bc BarChart) GetColorPalette() ColorPalette {
-	if bc.ColorPalette != nil {
-		return bc.ColorPalette
-	}
-	return AlternateColorPalette
-}

bar_chart_test.go

@@ -5,15 +5,20 @@ import (
 	"math"
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	assert "github.com/blendlabs/go-assert"
 )
 
 func TestBarChartRender(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
-		Width: 1024,
-		Title: "Test Title",
+		Width:      1024,
+		Title:      "Test Title",
+		TitleStyle: StyleShow(),
+		XAxis:      StyleShow(),
+		YAxis: YAxis{
+			Style: StyleShow(),
+		},
 		Bars: []Value{
 			{Value: 1.0, Label: "One"},
 			{Value: 2.0, Label: "Two"},
@@ -25,16 +30,21 @@ func TestBarChartRender(t *testing.T) {
 
 	buf := bytes.NewBuffer([]byte{})
 	err := bc.Render(PNG, buf)
-	testutil.AssertNil(t, err)
-	testutil.AssertNotZero(t, buf.Len())
+	assert.Nil(err)
+	assert.NotZero(buf.Len())
 }
 
 func TestBarChartRenderZero(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
-		Width: 1024,
-		Title: "Test Title",
+		Width:      1024,
+		Title:      "Test Title",
+		TitleStyle: StyleShow(),
+		XAxis:      StyleShow(),
+		YAxis: YAxis{
+			Style: StyleShow(),
+		},
 		Bars: []Value{
 			{Value: 0.0, Label: "One"},
 			{Value: 0.0, Label: "Two"},
@@ -43,64 +53,64 @@ func TestBarChartRenderZero(t *testing.T) {
 
 	buf := bytes.NewBuffer([]byte{})
 	err := bc.Render(PNG, buf)
-	testutil.AssertNotNil(t, err)
+	assert.NotNil(err)
 }
 
 func TestBarChartProps(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{}
 
-	testutil.AssertEqual(t, DefaultDPI, bc.GetDPI())
+	assert.Equal(DefaultDPI, bc.GetDPI())
 	bc.DPI = 100
-	testutil.AssertEqual(t, 100, bc.GetDPI())
+	assert.Equal(100, bc.GetDPI())
 
-	testutil.AssertNil(t, bc.GetFont())
+	assert.Nil(bc.GetFont())
 	f, err := GetDefaultFont()
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 	bc.Font = f
-	testutil.AssertNotNil(t, bc.GetFont())
+	assert.NotNil(bc.GetFont())
 
-	testutil.AssertEqual(t, DefaultChartWidth, bc.GetWidth())
+	assert.Equal(DefaultChartWidth, bc.GetWidth())
 	bc.Width = DefaultChartWidth - 1
-	testutil.AssertEqual(t, DefaultChartWidth-1, bc.GetWidth())
+	assert.Equal(DefaultChartWidth-1, bc.GetWidth())
 
-	testutil.AssertEqual(t, DefaultChartHeight, bc.GetHeight())
+	assert.Equal(DefaultChartHeight, bc.GetHeight())
 	bc.Height = DefaultChartHeight - 1
-	testutil.AssertEqual(t, DefaultChartHeight-1, bc.GetHeight())
+	assert.Equal(DefaultChartHeight-1, bc.GetHeight())
 
-	testutil.AssertEqual(t, DefaultBarSpacing, bc.GetBarSpacing())
+	assert.Equal(DefaultBarSpacing, bc.GetBarSpacing())
 	bc.BarSpacing = 150
-	testutil.AssertEqual(t, 150, bc.GetBarSpacing())
+	assert.Equal(150, bc.GetBarSpacing())
 
-	testutil.AssertEqual(t, DefaultBarWidth, bc.GetBarWidth())
+	assert.Equal(DefaultBarWidth, bc.GetBarWidth())
 	bc.BarWidth = 75
-	testutil.AssertEqual(t, 75, bc.GetBarWidth())
+	assert.Equal(75, bc.GetBarWidth())
 }
 
 func TestBarChartRenderNoBars(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{}
 	err := bc.Render(PNG, bytes.NewBuffer([]byte{}))
-	testutil.AssertNotNil(t, err)
+	assert.NotNil(err)
 }
 
 func TestBarChartGetRanges(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{}
 
 	yr := bc.getRanges()
-	testutil.AssertNotNil(t, yr)
-	testutil.AssertFalse(t, yr.IsZero())
+	assert.NotNil(yr)
+	assert.False(yr.IsZero())
 
-	testutil.AssertEqual(t, -math.MaxFloat64, yr.GetMax())
-	testutil.AssertEqual(t, math.MaxFloat64, yr.GetMin())
+	assert.Equal(-math.MaxFloat64, yr.GetMax())
+	assert.Equal(math.MaxFloat64, yr.GetMin())
 }
 
 func TestBarChartGetRangesBarsMinMax(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
 		Bars: []Value{
@@ -110,15 +120,15 @@ func TestBarChartGetRangesBarsMinMax(t *testing.T) {
 	}
 
 	yr := bc.getRanges()
-	testutil.AssertNotNil(t, yr)
-	testutil.AssertFalse(t, yr.IsZero())
+	assert.NotNil(yr)
+	assert.False(yr.IsZero())
 
-	testutil.AssertEqual(t, 10, yr.GetMax())
-	testutil.AssertEqual(t, 1, yr.GetMin())
+	assert.Equal(10, yr.GetMax())
+	assert.Equal(1, yr.GetMin())
 }
 
 func TestBarChartGetRangesMinMax(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
 		YAxis: YAxis{
@@ -138,15 +148,15 @@ func TestBarChartGetRangesMinMax(t *testing.T) {
 	}
 
 	yr := bc.getRanges()
-	testutil.AssertNotNil(t, yr)
-	testutil.AssertFalse(t, yr.IsZero())
+	assert.NotNil(yr)
+	assert.False(yr.IsZero())
 
-	testutil.AssertEqual(t, 15, yr.GetMax())
-	testutil.AssertEqual(t, 5, yr.GetMin())
+	assert.Equal(15, yr.GetMax())
+	assert.Equal(5, yr.GetMin())
 }
 
 func TestBarChartGetRangesTicksMinMax(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
 		YAxis: YAxis{
@@ -162,56 +172,57 @@ func TestBarChartGetRangesTicksMinMax(t *testing.T) {
 	}
 
 	yr := bc.getRanges()
-	testutil.AssertNotNil(t, yr)
-	testutil.AssertFalse(t, yr.IsZero())
+	assert.NotNil(yr)
+	assert.False(yr.IsZero())
 
-	testutil.AssertEqual(t, 11, yr.GetMax())
-	testutil.AssertEqual(t, 7, yr.GetMin())
+	assert.Equal(11, yr.GetMax())
+	assert.Equal(7, yr.GetMin())
 }
 
 func TestBarChartHasAxes(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{}
-	testutil.AssertTrue(t, bc.hasAxes())
+	assert.False(bc.hasAxes())
 	bc.YAxis = YAxis{
-		Style: Hidden(),
+		Style: StyleShow(),
 	}
-	testutil.AssertFalse(t, bc.hasAxes())
+
+	assert.True(bc.hasAxes())
 }
 
 func TestBarChartGetDefaultCanvasBox(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{}
 	b := bc.getDefaultCanvasBox()
-	testutil.AssertFalse(t, b.IsZero())
+	assert.False(b.IsZero())
 }
 
 func TestBarChartSetRangeDomains(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{}
 	cb := bc.box()
 	yr := bc.getRanges()
 	yr2 := bc.setRangeDomains(cb, yr)
-	testutil.AssertNotZero(t, yr2.GetDomain())
+	assert.NotZero(yr2.GetDomain())
 }
 
 func TestBarChartGetValueFormatters(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{}
 	vf := bc.getValueFormatters()
-	testutil.AssertNotNil(t, vf)
-	testutil.AssertEqual(t, "1234.00", vf(1234.0))
+	assert.NotNil(vf)
+	assert.Equal("1234.00", vf(1234.0))
 
 	bc.YAxis.ValueFormatter = func(_ interface{}) string { return "test" }
-	testutil.AssertEqual(t, "test", bc.getValueFormatters()(1234))
+	assert.Equal("test", bc.getValueFormatters()(1234))
 }
 
 func TestBarChartGetAxesTicks(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
 		Bars: []Value{
@@ -222,21 +233,20 @@ func TestBarChartGetAxesTicks(t *testing.T) {
 	}
 
 	r, err := PNG(128, 128)
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 	yr := bc.getRanges()
 	yf := bc.getValueFormatters()
 
-	bc.YAxis.Style.Hidden = true
 	ticks := bc.getAxesTicks(r, yr, yf)
-	testutil.AssertEmpty(t, ticks)
+	assert.Empty(ticks)
 
-	bc.YAxis.Style.Hidden = false
+	bc.YAxis.Style.Show = true
 	ticks = bc.getAxesTicks(r, yr, yf)
-	testutil.AssertLen(t, ticks, 2)
+	assert.Len(ticks, 2)
 }
 
 func TestBarChartCalculateEffectiveBarSpacing(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
 		Width:    1024,
@@ -251,15 +261,15 @@ func TestBarChartCalculateEffectiveBarSpacing(t *testing.T) {
 	}
 
 	spacing := bc.calculateEffectiveBarSpacing(bc.box())
-	testutil.AssertNotZero(t, spacing)
+	assert.NotZero(spacing)
 
 	bc.BarWidth = 250
 	spacing = bc.calculateEffectiveBarSpacing(bc.box())
-	testutil.AssertZero(t, spacing)
+	assert.Zero(spacing)
 }
 
 func TestBarChartCalculateEffectiveBarWidth(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BarChart{
 		Width:    1024,
@@ -276,35 +286,35 @@ func TestBarChartCalculateEffectiveBarWidth(t *testing.T) {
 	cb := bc.box()
 
 	spacing := bc.calculateEffectiveBarSpacing(bc.box())
-	testutil.AssertNotZero(t, spacing)
+	assert.NotZero(spacing)
 
 	barWidth := bc.calculateEffectiveBarWidth(bc.box(), spacing)
-	testutil.AssertEqual(t, 10, barWidth)
+	assert.Equal(10, barWidth)
 
 	bc.BarWidth = 250
 	spacing = bc.calculateEffectiveBarSpacing(bc.box())
-	testutil.AssertZero(t, spacing)
+	assert.Zero(spacing)
 	barWidth = bc.calculateEffectiveBarWidth(bc.box(), spacing)
-	testutil.AssertEqual(t, 199, barWidth)
+	assert.Equal(199, barWidth)
 
-	testutil.AssertEqual(t, cb.Width()+1, bc.calculateTotalBarWidth(barWidth, spacing))
+	assert.Equal(cb.Width()+1, bc.calculateTotalBarWidth(barWidth, spacing))
 
 	bw, bs, total := bc.calculateScaledTotalWidth(cb)
-	testutil.AssertEqual(t, spacing, bs)
-	testutil.AssertEqual(t, barWidth, bw)
-	testutil.AssertEqual(t, cb.Width()+1, total)
+	assert.Equal(spacing, bs)
+	assert.Equal(barWidth, bw)
+	assert.Equal(cb.Width()+1, total)
 }
 
 func TestBarChatGetTitleFontSize(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 	size := BarChart{Width: 2049, Height: 2049}.getTitleFontSize()
-	testutil.AssertEqual(t, 48, size)
+	assert.Equal(48, size)
 	size = BarChart{Width: 1025, Height: 1025}.getTitleFontSize()
-	testutil.AssertEqual(t, 24, size)
+	assert.Equal(24, size)
 	size = BarChart{Width: 513, Height: 513}.getTitleFontSize()
-	testutil.AssertEqual(t, 18, size)
+	assert.Equal(18, size)
 	size = BarChart{Width: 257, Height: 257}.getTitleFontSize()
-	testutil.AssertEqual(t, 12, size)
+	assert.Equal(12, size)
 	size = BarChart{Width: 128, Height: 128}.getTitleFontSize()
-	testutil.AssertEqual(t, 10, size)
+	assert.Equal(10, size)
 }

bollinger_band_series.go

@@ -2,11 +2,7 @@ package chart
 
 import (
 	"fmt"
-)
-
-// Interface Assertions.
-var (
-	_ Series = (*BollingerBandsSeries)(nil)
+	"math"
 )
 
 // BollingerBandsSeries draws bollinger bands for an inner series.
@@ -18,9 +14,9 @@ type BollingerBandsSeries struct {
 
 	Period      int
 	K           float64
-	InnerSeries ValuesProvider
+	InnerSeries ValueProvider
 
-	valueBuffer *ValueBuffer
+	valueBuffer *RingBuffer
 }
 
 // GetName returns the name of the time series.
@@ -46,9 +42,7 @@ func (bbs BollingerBandsSeries) GetPeriod() int {
 	return bbs.Period
 }
 
-// GetK returns the K value, or the number of standard deviations above and below
-// to band the simple moving average with.
-// Typical K value is 2.0.
+// GetK returns the K value.
 func (bbs BollingerBandsSeries) GetK(defaults ...float64) float64 {
 	if bbs.K == 0 {
 		if len(defaults) > 0 {
@@ -60,35 +54,35 @@ func (bbs BollingerBandsSeries) GetK(defaults ...float64) float64 {
 }
 
 // Len returns the number of elements in the series.
-func (bbs BollingerBandsSeries) Len() int {
+func (bbs *BollingerBandsSeries) Len() int {
 	return bbs.InnerSeries.Len()
 }
 
-// GetBoundedValues gets the bounded value for the series.
-func (bbs *BollingerBandsSeries) GetBoundedValues(index int) (x, y1, y2 float64) {
+// GetBoundedValue gets the bounded value for the series.
+func (bbs *BollingerBandsSeries) GetBoundedValue(index int) (x, y1, y2 float64) {
 	if bbs.InnerSeries == nil {
 		return
 	}
 	if bbs.valueBuffer == nil || index == 0 {
-		bbs.valueBuffer = NewValueBufferWithCapacity(bbs.GetPeriod())
+		bbs.valueBuffer = NewRingBufferWithCapacity(bbs.GetPeriod())
 	}
 	if bbs.valueBuffer.Len() >= bbs.GetPeriod() {
 		bbs.valueBuffer.Dequeue()
 	}
-	px, py := bbs.InnerSeries.GetValues(index)
+	px, py := bbs.InnerSeries.GetValue(index)
 	bbs.valueBuffer.Enqueue(py)
 	x = px
 
-	ay := Seq{bbs.valueBuffer}.Average()
-	std := Seq{bbs.valueBuffer}.StdDev()
+	ay := bbs.getAverage(bbs.valueBuffer)
+	std := bbs.getStdDev(bbs.valueBuffer)
 
 	y1 = ay + (bbs.GetK() * std)
 	y2 = ay - (bbs.GetK() * std)
 	return
 }
 
-// GetBoundedLastValues returns the last bounded value for the series.
-func (bbs *BollingerBandsSeries) GetBoundedLastValues() (x, y1, y2 float64) {
+// GetBoundedLastValue returns the last bounded value for the series.
+func (bbs *BollingerBandsSeries) GetBoundedLastValue() (x, y1, y2 float64) {
 	if bbs.InnerSeries == nil {
 		return
 	}
@@ -99,15 +93,15 @@ func (bbs *BollingerBandsSeries) GetBoundedLastValues() (x, y1, y2 float64) {
 		startAt = 0
 	}
 
-	vb := NewValueBufferWithCapacity(period)
+	vb := NewRingBufferWithCapacity(period)
 	for index := startAt; index < seriesLength; index++ {
-		xn, yn := bbs.InnerSeries.GetValues(index)
+		xn, yn := bbs.InnerSeries.GetValue(index)
 		vb.Enqueue(yn)
 		x = xn
 	}
 
-	ay := Seq{vb}.Average()
-	std := Seq{vb}.StdDev()
+	ay := bbs.getAverage(vb)
+	std := bbs.getStdDev(vb)
 
 	y1 = ay + (bbs.GetK() * std)
 	y2 = ay - (bbs.GetK() * std)
@@ -126,6 +120,37 @@ func (bbs *BollingerBandsSeries) Render(r Renderer, canvasBox Box, xrange, yrang
 	Draw.BoundedSeries(r, canvasBox, xrange, yrange, s, bbs, bbs.GetPeriod())
 }
 
+func (bbs BollingerBandsSeries) getAverage(valueBuffer *RingBuffer) float64 {
+	var accum float64
+	valueBuffer.Each(func(v interface{}) {
+		if typed, isTyped := v.(float64); isTyped {
+			accum += typed
+		}
+	})
+	return accum / float64(valueBuffer.Len())
+}
+
+func (bbs BollingerBandsSeries) getVariance(valueBuffer *RingBuffer) float64 {
+	if valueBuffer.Len() == 0 {
+		return 0
+	}
+
+	var variance float64
+	m := bbs.getAverage(valueBuffer)
+
+	valueBuffer.Each(func(v interface{}) {
+		if n, isTyped := v.(float64); isTyped {
+			variance += (float64(n) - m) * (float64(n) - m)
+		}
+	})
+
+	return variance / float64(valueBuffer.Len())
+}
+
+func (bbs BollingerBandsSeries) getStdDev(valueBuffer *RingBuffer) float64 {
+	return math.Pow(bbs.getVariance(valueBuffer), 0.5)
+}
+
 // Validate validates the series.
 func (bbs BollingerBandsSeries) Validate() error {
 	if bbs.InnerSeries == nil {

bollinger_band_series_test.go

@@ -1,19 +1,18 @@
 package chart
 
 import (
-	"fmt"
 	"math"
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	"github.com/blendlabs/go-assert"
 )
 
 func TestBollingerBandSeries(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
-	s1 := mockValuesProvider{
-		X: LinearRange(1.0, 100.0),
-		Y: RandomValuesWithMax(100, 1024),
+	s1 := mockValueProvider{
+		X: Sequence.Float64(1.0, 100.0),
+		Y: Sequence.Random(100, 1024),
 	}
 
 	bbs := &BollingerBandsSeries{
@@ -25,28 +24,28 @@ func TestBollingerBandSeries(t *testing.T) {
 	y2values := make([]float64, 100)
 
 	for x := 0; x < 100; x++ {
-		xvalues[x], y1values[x], y2values[x] = bbs.GetBoundedValues(x)
+		xvalues[x], y1values[x], y2values[x] = bbs.GetBoundedValue(x)
 	}
 
 	for x := bbs.GetPeriod(); x < 100; x++ {
-		testutil.AssertTrue(t, y1values[x] > y2values[x], fmt.Sprintf("%v vs. %v", y1values[x], y2values[x]))
+		assert.True(y1values[x] > y2values[x])
 	}
 }
 
 func TestBollingerBandLastValue(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
-	s1 := mockValuesProvider{
-		X: LinearRange(1.0, 100.0),
-		Y: LinearRange(1.0, 100.0),
+	s1 := mockValueProvider{
+		X: Sequence.Float64(1.0, 100.0),
+		Y: Sequence.Float64(1.0, 100.0),
 	}
 
 	bbs := &BollingerBandsSeries{
 		InnerSeries: s1,
 	}
 
-	x, y1, y2 := bbs.GetBoundedLastValues()
-	testutil.AssertEqual(t, 100.0, x)
-	testutil.AssertEqual(t, 101, math.Floor(y1))
-	testutil.AssertEqual(t, 83, math.Floor(y2))
+	x, y1, y2 := bbs.GetBoundedLastValue()
+	assert.Equal(100.0, x)
+	assert.Equal(101, math.Floor(y1))
+	assert.Equal(83, math.Floor(y2))
 }

bounded_last_values_annotation_series.go

@@ -1,36 +0,0 @@
-package chart
-
-import "fmt"
-
-// BoundedLastValuesAnnotationSeries returns a last value annotation series for a bounded values provider.
-func BoundedLastValuesAnnotationSeries(innerSeries FullBoundedValuesProvider, vfs ...ValueFormatter) AnnotationSeries {
-	lvx, lvy1, lvy2 := innerSeries.GetBoundedLastValues()
-
-	var vf ValueFormatter
-	if len(vfs) > 0 {
-		vf = vfs[0]
-	} else if typed, isTyped := innerSeries.(ValueFormatterProvider); isTyped {
-		_, vf = typed.GetValueFormatters()
-	} else {
-		vf = FloatValueFormatter
-	}
-
-	label1 := vf(lvy1)
-	label2 := vf(lvy2)
-
-	var seriesName string
-	var seriesStyle Style
-	if typed, isTyped := innerSeries.(Series); isTyped {
-		seriesName = fmt.Sprintf("%s - Last Values", typed.GetName())
-		seriesStyle = typed.GetStyle()
-	}
-
-	return AnnotationSeries{
-		Name:  seriesName,
-		Style: seriesStyle,
-		Annotations: []Value2{
-			{XValue: lvx, YValue: lvy1, Label: label1},
-			{XValue: lvx, YValue: lvy2, Label: label2},
-		},
-	}
-}

box.go

@@ -89,12 +89,12 @@ func (b Box) GetBottom(defaults ...int) int {
 
 // Width returns the width
 func (b Box) Width() int {
-	return AbsInt(b.Right - b.Left)
+	return Math.AbsInt(b.Right - b.Left)
 }
 
 // Height returns the height
 func (b Box) Height() int {
-	return AbsInt(b.Bottom - b.Top)
+	return Math.AbsInt(b.Bottom - b.Top)
 }
 
 // Center returns the center of the box
@@ -146,10 +146,10 @@ func (b Box) Equals(other Box) bool {
 // Grow grows a box based on another box.
 func (b Box) Grow(other Box) Box {
 	return Box{
-		Top:    MinInt(b.Top, other.Top),
-		Left:   MinInt(b.Left, other.Left),
-		Right:  MaxInt(b.Right, other.Right),
-		Bottom: MaxInt(b.Bottom, other.Bottom),
+		Top:    Math.MinInt(b.Top, other.Top),
+		Left:   Math.MinInt(b.Left, other.Left),
+		Right:  Math.MaxInt(b.Right, other.Right),
+		Bottom: Math.MaxInt(b.Bottom, other.Bottom),
 	}
 }
 
@@ -220,10 +220,10 @@ func (b Box) Fit(other Box) Box {
 func (b Box) Constrain(other Box) Box {
 	newBox := b.Clone()
 
-	newBox.Top = MaxInt(newBox.Top, other.Top)
-	newBox.Left = MaxInt(newBox.Left, other.Left)
-	newBox.Right = MinInt(newBox.Right, other.Right)
-	newBox.Bottom = MinInt(newBox.Bottom, other.Bottom)
+	newBox.Top = Math.MaxInt(newBox.Top, other.Top)
+	newBox.Left = Math.MaxInt(newBox.Left, other.Left)
+	newBox.Right = Math.MinInt(newBox.Right, other.Right)
+	newBox.Bottom = Math.MinInt(newBox.Bottom, other.Bottom)
 
 	return newBox
 }
@@ -254,22 +254,6 @@ func (b Box) OuterConstrain(bounds, other Box) Box {
 	return newBox
 }
 
-func (b Box) Validate() error {
-	if b.Left < 0 {
-		return fmt.Errorf("invalid left; must be >= 0")
-	}
-	if b.Right < 0 {
-		return fmt.Errorf("invalid right; must be > 0")
-	}
-	if b.Top < 0 {
-		return fmt.Errorf("invalid top; must be > 0")
-	}
-	if b.Bottom < 0 {
-		return fmt.Errorf("invalid bottom; must be > 0")
-	}
-	return nil
-}
-
 // BoxCorners is a box with independent corners.
 type BoxCorners struct {
 	TopLeft, TopRight, BottomRight, BottomLeft Point
@@ -278,36 +262,36 @@ type BoxCorners struct {
 // Box return the BoxCorners as a regular box.
 func (bc BoxCorners) Box() Box {
 	return Box{
-		Top:    MinInt(bc.TopLeft.Y, bc.TopRight.Y),
-		Left:   MinInt(bc.TopLeft.X, bc.BottomLeft.X),
-		Right:  MaxInt(bc.TopRight.X, bc.BottomRight.X),
-		Bottom: MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y),
+		Top:    Math.MinInt(bc.TopLeft.Y, bc.TopRight.Y),
+		Left:   Math.MinInt(bc.TopLeft.X, bc.BottomLeft.X),
+		Right:  Math.MaxInt(bc.TopRight.X, bc.BottomRight.X),
+		Bottom: Math.MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y),
 	}
 }
 
 // Width returns the width
 func (bc BoxCorners) Width() int {
-	minLeft := MinInt(bc.TopLeft.X, bc.BottomLeft.X)
-	maxRight := MaxInt(bc.TopRight.X, bc.BottomRight.X)
+	minLeft := Math.MinInt(bc.TopLeft.X, bc.BottomLeft.X)
+	maxRight := Math.MaxInt(bc.TopRight.X, bc.BottomRight.X)
 	return maxRight - minLeft
 }
 
 // Height returns the height
 func (bc BoxCorners) Height() int {
-	minTop := MinInt(bc.TopLeft.Y, bc.TopRight.Y)
-	maxBottom := MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y)
+	minTop := Math.MinInt(bc.TopLeft.Y, bc.TopRight.Y)
+	maxBottom := Math.MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y)
 	return maxBottom - minTop
 }
 
 // Center returns the center of the box
 func (bc BoxCorners) Center() (x, y int) {
 
-	left := MeanInt(bc.TopLeft.X, bc.BottomLeft.X)
-	right := MeanInt(bc.TopRight.X, bc.BottomRight.X)
+	left := Math.MeanInt(bc.TopLeft.X, bc.BottomLeft.X)
+	right := Math.MeanInt(bc.TopRight.X, bc.BottomRight.X)
 	x = ((right - left) >> 1) + left
 
-	top := MeanInt(bc.TopLeft.Y, bc.TopRight.Y)
-	bottom := MeanInt(bc.BottomLeft.Y, bc.BottomRight.Y)
+	top := Math.MeanInt(bc.TopLeft.Y, bc.TopRight.Y)
+	bottom := Math.MeanInt(bc.BottomLeft.Y, bc.BottomRight.Y)
 	y = ((bottom - top) >> 1) + top
 
 	return
@@ -317,12 +301,12 @@ func (bc BoxCorners) Center() (x, y int) {
 func (bc BoxCorners) Rotate(thetaDegrees float64) BoxCorners {
 	cx, cy := bc.Center()
 
-	thetaRadians := DegreesToRadians(thetaDegrees)
+	thetaRadians := Math.DegreesToRadians(thetaDegrees)
 
-	tlx, tly := RotateCoordinate(cx, cy, bc.TopLeft.X, bc.TopLeft.Y, thetaRadians)
-	trx, try := RotateCoordinate(cx, cy, bc.TopRight.X, bc.TopRight.Y, thetaRadians)
-	brx, bry := RotateCoordinate(cx, cy, bc.BottomRight.X, bc.BottomRight.Y, thetaRadians)
-	blx, bly := RotateCoordinate(cx, cy, bc.BottomLeft.X, bc.BottomLeft.Y, thetaRadians)
+	tlx, tly := Math.RotateCoordinate(cx, cy, bc.TopLeft.X, bc.TopLeft.Y, thetaRadians)
+	trx, try := Math.RotateCoordinate(cx, cy, bc.TopRight.X, bc.TopRight.Y, thetaRadians)
+	brx, bry := Math.RotateCoordinate(cx, cy, bc.BottomRight.X, bc.BottomRight.Y, thetaRadians)
+	blx, bly := Math.RotateCoordinate(cx, cy, bc.BottomLeft.X, bc.BottomLeft.Y, thetaRadians)
 
 	return BoxCorners{
 		TopLeft:     Point{tlx, tly},

box_test.go

@@ -4,131 +4,131 @@ import (
 	"math"
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	"github.com/blendlabs/go-assert"
 )
 
 func TestBoxClone(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 	a := Box{Top: 5, Left: 5, Right: 15, Bottom: 15}
 	b := a.Clone()
-	testutil.AssertTrue(t, a.Equals(b))
-	testutil.AssertTrue(t, b.Equals(a))
+	assert.True(a.Equals(b))
+	assert.True(b.Equals(a))
 }
 
 func TestBoxEquals(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	a := Box{Top: 5, Left: 5, Right: 15, Bottom: 15}
 	b := Box{Top: 10, Left: 10, Right: 30, Bottom: 30}
 	c := Box{Top: 5, Left: 5, Right: 15, Bottom: 15}
-	testutil.AssertTrue(t, a.Equals(a))
-	testutil.AssertTrue(t, a.Equals(c))
-	testutil.AssertTrue(t, c.Equals(a))
-	testutil.AssertFalse(t, a.Equals(b))
-	testutil.AssertFalse(t, c.Equals(b))
-	testutil.AssertFalse(t, b.Equals(a))
-	testutil.AssertFalse(t, b.Equals(c))
+	assert.True(a.Equals(a))
+	assert.True(a.Equals(c))
+	assert.True(c.Equals(a))
+	assert.False(a.Equals(b))
+	assert.False(c.Equals(b))
+	assert.False(b.Equals(a))
+	assert.False(b.Equals(c))
 }
 
 func TestBoxIsBiggerThan(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	a := Box{Top: 5, Left: 5, Right: 25, Bottom: 25}
 	b := Box{Top: 10, Left: 10, Right: 20, Bottom: 20} // only half bigger
 	c := Box{Top: 1, Left: 1, Right: 30, Bottom: 30}   //bigger
-	testutil.AssertTrue(t, a.IsBiggerThan(b))
-	testutil.AssertFalse(t, a.IsBiggerThan(c))
-	testutil.AssertTrue(t, c.IsBiggerThan(a))
+	assert.True(a.IsBiggerThan(b))
+	assert.False(a.IsBiggerThan(c))
+	assert.True(c.IsBiggerThan(a))
 }
 
 func TestBoxIsSmallerThan(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	a := Box{Top: 5, Left: 5, Right: 25, Bottom: 25}
 	b := Box{Top: 10, Left: 10, Right: 20, Bottom: 20} // only half bigger
 	c := Box{Top: 1, Left: 1, Right: 30, Bottom: 30}   //bigger
-	testutil.AssertFalse(t, a.IsSmallerThan(b))
-	testutil.AssertTrue(t, a.IsSmallerThan(c))
-	testutil.AssertFalse(t, c.IsSmallerThan(a))
+	assert.False(a.IsSmallerThan(b))
+	assert.True(a.IsSmallerThan(c))
+	assert.False(c.IsSmallerThan(a))
 }
 
 func TestBoxGrow(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	a := Box{Top: 1, Left: 2, Right: 15, Bottom: 15}
 	b := Box{Top: 4, Left: 5, Right: 30, Bottom: 35}
 	c := a.Grow(b)
-	testutil.AssertFalse(t, c.Equals(b))
-	testutil.AssertFalse(t, c.Equals(a))
-	testutil.AssertEqual(t, 1, c.Top)
-	testutil.AssertEqual(t, 2, c.Left)
-	testutil.AssertEqual(t, 30, c.Right)
-	testutil.AssertEqual(t, 35, c.Bottom)
+	assert.False(c.Equals(b))
+	assert.False(c.Equals(a))
+	assert.Equal(1, c.Top)
+	assert.Equal(2, c.Left)
+	assert.Equal(30, c.Right)
+	assert.Equal(35, c.Bottom)
 }
 
 func TestBoxFit(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	a := Box{Top: 64, Left: 64, Right: 192, Bottom: 192}
 	b := Box{Top: 16, Left: 16, Right: 256, Bottom: 170}
 	c := Box{Top: 16, Left: 16, Right: 170, Bottom: 256}
 
 	fab := a.Fit(b)
-	testutil.AssertEqual(t, a.Left, fab.Left)
-	testutil.AssertEqual(t, a.Right, fab.Right)
-	testutil.AssertTrue(t, fab.Top < fab.Bottom)
-	testutil.AssertTrue(t, fab.Left < fab.Right)
-	testutil.AssertTrue(t, math.Abs(b.Aspect()-fab.Aspect()) < 0.02)
+	assert.Equal(a.Left, fab.Left)
+	assert.Equal(a.Right, fab.Right)
+	assert.True(fab.Top < fab.Bottom)
+	assert.True(fab.Left < fab.Right)
+	assert.True(math.Abs(b.Aspect()-fab.Aspect()) < 0.02)
 
 	fac := a.Fit(c)
-	testutil.AssertEqual(t, a.Top, fac.Top)
-	testutil.AssertEqual(t, a.Bottom, fac.Bottom)
-	testutil.AssertTrue(t, math.Abs(c.Aspect()-fac.Aspect()) < 0.02)
+	assert.Equal(a.Top, fac.Top)
+	assert.Equal(a.Bottom, fac.Bottom)
+	assert.True(math.Abs(c.Aspect()-fac.Aspect()) < 0.02)
 }
 
 func TestBoxConstrain(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	a := Box{Top: 64, Left: 64, Right: 192, Bottom: 192}
 	b := Box{Top: 16, Left: 16, Right: 256, Bottom: 170}
 	c := Box{Top: 16, Left: 16, Right: 170, Bottom: 256}
 
 	cab := a.Constrain(b)
-	testutil.AssertEqual(t, 64, cab.Top)
-	testutil.AssertEqual(t, 64, cab.Left)
-	testutil.AssertEqual(t, 192, cab.Right)
-	testutil.AssertEqual(t, 170, cab.Bottom)
+	assert.Equal(64, cab.Top)
+	assert.Equal(64, cab.Left)
+	assert.Equal(192, cab.Right)
+	assert.Equal(170, cab.Bottom)
 
 	cac := a.Constrain(c)
-	testutil.AssertEqual(t, 64, cac.Top)
-	testutil.AssertEqual(t, 64, cac.Left)
-	testutil.AssertEqual(t, 170, cac.Right)
-	testutil.AssertEqual(t, 192, cac.Bottom)
+	assert.Equal(64, cac.Top)
+	assert.Equal(64, cac.Left)
+	assert.Equal(170, cac.Right)
+	assert.Equal(192, cac.Bottom)
 }
 
 func TestBoxOuterConstrain(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	box := NewBox(0, 0, 100, 100)
 	canvas := NewBox(5, 5, 95, 95)
 	taller := NewBox(-10, 5, 50, 50)
 
 	c := canvas.OuterConstrain(box, taller)
-	testutil.AssertEqual(t, 15, c.Top, c.String())
-	testutil.AssertEqual(t, 5, c.Left, c.String())
-	testutil.AssertEqual(t, 95, c.Right, c.String())
-	testutil.AssertEqual(t, 95, c.Bottom, c.String())
+	assert.Equal(15, c.Top, c.String())
+	assert.Equal(5, c.Left, c.String())
+	assert.Equal(95, c.Right, c.String())
+	assert.Equal(95, c.Bottom, c.String())
 
 	wider := NewBox(5, 5, 110, 50)
 	d := canvas.OuterConstrain(box, wider)
-	testutil.AssertEqual(t, 5, d.Top, d.String())
-	testutil.AssertEqual(t, 5, d.Left, d.String())
-	testutil.AssertEqual(t, 85, d.Right, d.String())
-	testutil.AssertEqual(t, 95, d.Bottom, d.String())
+	assert.Equal(5, d.Top, d.String())
+	assert.Equal(5, d.Left, d.String())
+	assert.Equal(85, d.Right, d.String())
+	assert.Equal(95, d.Bottom, d.String())
 }
 
 func TestBoxShift(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	b := Box{
 		Top:    5,
@@ -138,14 +138,14 @@ func TestBoxShift(t *testing.T) {
 	}
 
 	shifted := b.Shift(1, 2)
-	testutil.AssertEqual(t, 7, shifted.Top)
-	testutil.AssertEqual(t, 6, shifted.Left)
-	testutil.AssertEqual(t, 11, shifted.Right)
-	testutil.AssertEqual(t, 12, shifted.Bottom)
+	assert.Equal(7, shifted.Top)
+	assert.Equal(6, shifted.Left)
+	assert.Equal(11, shifted.Right)
+	assert.Equal(12, shifted.Bottom)
 }
 
 func TestBoxCenter(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	b := Box{
 		Top:    10,
@@ -154,12 +154,12 @@ func TestBoxCenter(t *testing.T) {
 		Bottom: 30,
 	}
 	cx, cy := b.Center()
-	testutil.AssertEqual(t, 15, cx)
-	testutil.AssertEqual(t, 20, cy)
+	assert.Equal(15, cx)
+	assert.Equal(20, cy)
 }
 
 func TestBoxCornersCenter(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BoxCorners{
 		TopLeft:     Point{5, 5},
@@ -169,12 +169,12 @@ func TestBoxCornersCenter(t *testing.T) {
 	}
 
 	cx, cy := bc.Center()
-	testutil.AssertEqual(t, 10, cx)
-	testutil.AssertEqual(t, 10, cy)
+	assert.Equal(10, cx)
+	assert.Equal(10, cy)
 }
 
 func TestBoxCornersRotate(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	bc := BoxCorners{
 		TopLeft:     Point{5, 5},
@@ -184,5 +184,5 @@ func TestBoxCornersRotate(t *testing.T) {
 	}
 
 	rotated := bc.Rotate(45)
-	testutil.AssertTrue(t, rotated.TopLeft.Equals(Point{10, 3}), rotated.String())
+	assert.True(rotated.TopLeft.Equals(Point{10, 3}), rotated.String())
 }

chart.go

@@ -14,8 +14,6 @@ type Chart struct {
 	Title      string
 	TitleStyle Style
 
-	ColorPalette ColorPalette
-
 	Width  int
 	Height int
 	DPI    float64
@@ -32,8 +30,6 @@ type Chart struct {
 
 	Series   []Series
 	Elements []Renderable
-
-	Log Logger
 }
 
 // GetDPI returns the dpi for the chart.
@@ -76,8 +72,8 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 	if len(c.Series) == 0 {
 		return errors.New("please provide at least one series")
 	}
-	if err := c.checkHasVisibleSeries(); err != nil {
-		return err
+	if visibleSeriesErr := c.checkHasVisibleSeries(); visibleSeriesErr != nil {
+		return visibleSeriesErr
 	}
 
 	c.YAxisSecondary.AxisType = YAxisSecondary
@@ -102,13 +98,11 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 	xr, yr, yra := c.getRanges()
 	canvasBox := c.getDefaultCanvasBox()
 	xf, yf, yfa := c.getValueFormatters()
-
-	Debugf(c.Log, "chart; canvas box: %v", canvasBox)
-
 	xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
 
 	err = c.checkRanges(xr, yr, yra)
 	if err != nil {
+		// (try to) dump the raw background to the stream.
 		r.Save(w)
 		return err
 	}
@@ -118,8 +112,6 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 		canvasBox = c.getAxesAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xt, yt, yta)
 		xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
 
-		Debugf(c.Log, "chart; axes adjusted canvas box: %v", canvasBox)
-
 		// do a second pass in case things haven't settled yet.
 		xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
 		canvasBox = c.getAxesAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xt, yt, yta)
@@ -130,8 +122,6 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 		canvasBox = c.getAnnotationAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xf, yf, yfa)
 		xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
 		xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
-
-		Debugf(c.Log, "chart; annotation adjusted canvas box: %v", canvasBox)
 	}
 
 	c.drawCanvas(r, canvasBox)
@@ -150,14 +140,16 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 }
 
 func (c Chart) checkHasVisibleSeries() error {
+	hasVisibleSeries := false
 	var style Style
 	for _, s := range c.Series {
 		style = s.GetStyle()
-		if !style.Hidden {
-			return nil
-		}
+		hasVisibleSeries = hasVisibleSeries || (style.IsZero() || style.Show)
 	}
-	return fmt.Errorf("chart render; must have (1) visible series")
+	if !hasVisibleSeries {
+		return fmt.Errorf("must have (1) visible series; make sure if you set a style, you set .Show = true")
+	}
+	return nil
 }
 
 func (c Chart) validateSeries() error {
@@ -181,12 +173,12 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 	// note: a possible future optimization is to not scan the series values if
 	// all axis are represented by either custom ticks or custom ranges.
 	for _, s := range c.Series {
-		if !s.GetStyle().Hidden {
+		if s.GetStyle().IsZero() || s.GetStyle().Show {
 			seriesAxis := s.GetYAxis()
-			if bvp, isBoundedValuesProvider := s.(BoundedValuesProvider); isBoundedValuesProvider {
+			if bvp, isBoundedValueProvider := s.(BoundedValueProvider); isBoundedValueProvider {
 				seriesLength := bvp.Len()
 				for index := 0; index < seriesLength; index++ {
-					vx, vy1, vy2 := bvp.GetBoundedValues(index)
+					vx, vy1, vy2 := bvp.GetBoundedValue(index)
 
 					minx = math.Min(minx, vx)
 					maxx = math.Max(maxx, vx)
@@ -204,10 +196,10 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 						seriesMappedToSecondaryAxis = true
 					}
 				}
-			} else if vp, isValuesProvider := s.(ValuesProvider); isValuesProvider {
+			} else if vp, isValueProvider := s.(ValueProvider); isValueProvider {
 				seriesLength := vp.Len()
 				for index := 0; index < seriesLength; index++ {
-					vx, vy := vp.GetValues(index)
+					vx, vy := vp.GetValue(index)
 
 					minx = math.Min(minx, vx)
 					maxx = math.Max(maxx, vx)
@@ -268,14 +260,11 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 		yrange.SetMin(miny)
 		yrange.SetMax(maxy)
 
-		if !c.YAxis.Style.Hidden {
-			delta := yrange.GetDelta()
-			roundTo := GetRoundToForDelta(delta)
-			rmin, rmax := RoundDown(yrange.GetMin(), roundTo), RoundUp(yrange.GetMax(), roundTo)
-
-			yrange.SetMin(rmin)
-			yrange.SetMax(rmax)
-		}
+		delta := yrange.GetDelta()
+		roundTo := Math.GetRoundToForDelta(delta)
+		rmin, rmax := Math.RoundDown(yrange.GetMin(), roundTo), Math.RoundUp(yrange.GetMax(), roundTo)
+		yrange.SetMin(rmin)
+		yrange.SetMax(rmax)
 	}
 
 	if len(c.YAxisSecondary.Ticks) > 0 {
@@ -290,20 +279,17 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 		yrangeAlt.SetMin(minya)
 		yrangeAlt.SetMax(maxya)
 
-		if !c.YAxisSecondary.Style.Hidden {
-			delta := yrangeAlt.GetDelta()
-			roundTo := GetRoundToForDelta(delta)
-			rmin, rmax := RoundDown(yrangeAlt.GetMin(), roundTo), RoundUp(yrangeAlt.GetMax(), roundTo)
-			yrangeAlt.SetMin(rmin)
-			yrangeAlt.SetMax(rmax)
-		}
+		delta := yrangeAlt.GetDelta()
+		roundTo := Math.GetRoundToForDelta(delta)
+		rmin, rmax := Math.RoundDown(yrangeAlt.GetMin(), roundTo), Math.RoundUp(yrangeAlt.GetMax(), roundTo)
+		yrangeAlt.SetMin(rmin)
+		yrangeAlt.SetMax(rmax)
 	}
 
 	return
 }
 
 func (c Chart) checkRanges(xr, yr, yra Range) error {
-	Debugf(c.Log, "checking xrange: %v", xr)
 	xDelta := xr.GetDelta()
 	if math.IsInf(xDelta, 0) {
 		return errors.New("infinite x-range delta")
@@ -315,7 +301,6 @@ func (c Chart) checkRanges(xr, yr, yra Range) error {
 		return errors.New("zero x-range delta; there needs to be at least (2) values")
 	}
 
-	Debugf(c.Log, "checking yrange: %v", yr)
 	yDelta := yr.GetDelta()
 	if math.IsInf(yDelta, 0) {
 		return errors.New("infinite y-range delta")
@@ -325,7 +310,6 @@ func (c Chart) checkRanges(xr, yr, yra Range) error {
 	}
 
 	if c.hasSecondarySeries() {
-		Debugf(c.Log, "checking secondary yrange: %v", yra)
 		yraDelta := yra.GetDelta()
 		if math.IsInf(yraDelta, 0) {
 			return errors.New("infinite secondary y-range delta")
@@ -356,29 +340,29 @@ func (c Chart) getValueFormatters() (x, y, ya ValueFormatter) {
 		}
 	}
 	if c.XAxis.ValueFormatter != nil {
-		x = c.XAxis.GetValueFormatter()
+		x = c.XAxis.ValueFormatter
 	}
 	if c.YAxis.ValueFormatter != nil {
-		y = c.YAxis.GetValueFormatter()
+		y = c.YAxis.ValueFormatter
 	}
 	if c.YAxisSecondary.ValueFormatter != nil {
-		ya = c.YAxisSecondary.GetValueFormatter()
+		ya = c.YAxisSecondary.ValueFormatter
 	}
 	return
 }
 
 func (c Chart) hasAxes() bool {
-	return !c.XAxis.Style.Hidden || !c.YAxis.Style.Hidden || !c.YAxisSecondary.Style.Hidden
+	return c.XAxis.Style.Show || c.YAxis.Style.Show || c.YAxisSecondary.Style.Show
 }
 
 func (c Chart) getAxesTicks(r Renderer, xr, yr, yar Range, xf, yf, yfa ValueFormatter) (xticks, yticks, yticksAlt []Tick) {
-	if !c.XAxis.Style.Hidden {
+	if c.XAxis.Style.Show {
 		xticks = c.XAxis.GetTicks(r, xr, c.styleDefaultsAxes(), xf)
 	}
-	if !c.YAxis.Style.Hidden {
+	if c.YAxis.Style.Show {
 		yticks = c.YAxis.GetTicks(r, yr, c.styleDefaultsAxes(), yf)
 	}
-	if !c.YAxisSecondary.Style.Hidden {
+	if c.YAxisSecondary.Style.Show {
 		yticksAlt = c.YAxisSecondary.GetTicks(r, yar, c.styleDefaultsAxes(), yfa)
 	}
 	return
@@ -386,19 +370,16 @@ func (c Chart) getAxesTicks(r Renderer, xr, yr, yar Range, xf, yf, yfa ValueForm
 
 func (c Chart) getAxesAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr, yra Range, xticks, yticks, yticksAlt []Tick) Box {
 	axesOuterBox := canvasBox.Clone()
-	if !c.XAxis.Style.Hidden {
+	if c.XAxis.Style.Show {
 		axesBounds := c.XAxis.Measure(r, canvasBox, xr, c.styleDefaultsAxes(), xticks)
-		Debugf(c.Log, "chart; x-axis measured %v", axesBounds)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
-	if !c.YAxis.Style.Hidden {
+	if c.YAxis.Style.Show {
 		axesBounds := c.YAxis.Measure(r, canvasBox, yr, c.styleDefaultsAxes(), yticks)
-		Debugf(c.Log, "chart; y-axis measured %v", axesBounds)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
-	if !c.YAxisSecondary.Style.Hidden && c.hasSecondarySeries() {
+	if c.YAxisSecondary.Style.Show {
 		axesBounds := c.YAxisSecondary.Measure(r, canvasBox, yra, c.styleDefaultsAxes(), yticksAlt)
-		Debugf(c.Log, "chart; y-axis secondary measured %v", axesBounds)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
 
@@ -415,7 +396,7 @@ func (c Chart) setRangeDomains(canvasBox Box, xr, yr, yra Range) (Range, Range,
 func (c Chart) hasAnnotationSeries() bool {
 	for _, s := range c.Series {
 		if as, isAnnotationSeries := s.(AnnotationSeries); isAnnotationSeries {
-			if !as.GetStyle().Hidden {
+			if as.Style.IsZero() || as.Style.Show {
 				return true
 			}
 		}
@@ -436,7 +417,7 @@ func (c Chart) getAnnotationAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr,
 	annotationSeriesBox := canvasBox.Clone()
 	for seriesIndex, s := range c.Series {
 		if as, isAnnotationSeries := s.(AnnotationSeries); isAnnotationSeries {
-			if !as.GetStyle().Hidden {
+			if as.Style.IsZero() || as.Style.Show {
 				style := c.styleDefaultsSeries(seriesIndex)
 				var annotationBounds Box
 				if as.YAxis == YAxisPrimary {
@@ -473,19 +454,19 @@ func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
 }
 
 func (c Chart) drawAxes(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt Range, xticks, yticks, yticksAlt []Tick) {
-	if !c.XAxis.Style.Hidden {
+	if c.XAxis.Style.Show {
 		c.XAxis.Render(r, canvasBox, xrange, c.styleDefaultsAxes(), xticks)
 	}
-	if !c.YAxis.Style.Hidden {
+	if c.YAxis.Style.Show {
 		c.YAxis.Render(r, canvasBox, yrange, c.styleDefaultsAxes(), yticks)
 	}
-	if !c.YAxisSecondary.Style.Hidden {
+	if c.YAxisSecondary.Style.Show {
 		c.YAxisSecondary.Render(r, canvasBox, yrangeAlt, c.styleDefaultsAxes(), yticksAlt)
 	}
 }
 
 func (c Chart) drawSeries(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt Range, s Series, seriesIndex int) {
-	if !s.GetStyle().Hidden {
+	if s.GetStyle().IsZero() || s.GetStyle().Show {
 		if s.GetYAxis() == YAxisPrimary {
 			s.Render(r, canvasBox, xrange, yrange, c.styleDefaultsSeries(seriesIndex))
 		} else if s.GetYAxis() == YAxisSecondary {
@@ -495,9 +476,9 @@ func (c Chart) drawSeries(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt R
 }
 
 func (c Chart) drawTitle(r Renderer) {
-	if len(c.Title) > 0 && !c.TitleStyle.Hidden {
+	if len(c.Title) > 0 && c.TitleStyle.Show {
 		r.SetFont(c.TitleStyle.GetFont(c.GetFont()))
-		r.SetFontColor(c.TitleStyle.GetFontColor(c.GetColorPalette().TextColor()))
+		r.SetFontColor(c.TitleStyle.GetFontColor(DefaultTextColor))
 		titleFontSize := c.TitleStyle.GetFontSize(DefaultTitleFontSize)
 		r.SetFontSize(titleFontSize)
 
@@ -515,24 +496,25 @@ func (c Chart) drawTitle(r Renderer) {
 
 func (c Chart) styleDefaultsBackground() Style {
 	return Style{
-		FillColor:   c.GetColorPalette().BackgroundColor(),
-		StrokeColor: c.GetColorPalette().BackgroundStrokeColor(),
+		FillColor:   DefaultBackgroundColor,
+		StrokeColor: DefaultBackgroundStrokeColor,
 		StrokeWidth: DefaultBackgroundStrokeWidth,
 	}
 }
 
 func (c Chart) styleDefaultsCanvas() Style {
 	return Style{
-		FillColor:   c.GetColorPalette().CanvasColor(),
-		StrokeColor: c.GetColorPalette().CanvasStrokeColor(),
+		FillColor:   DefaultCanvasColor,
+		StrokeColor: DefaultCanvasStrokeColor,
 		StrokeWidth: DefaultCanvasStrokeWidth,
 	}
 }
 
 func (c Chart) styleDefaultsSeries(seriesIndex int) Style {
+	strokeColor := GetDefaultColor(seriesIndex)
 	return Style{
-		DotColor:    c.GetColorPalette().GetSeriesColor(seriesIndex),
-		StrokeColor: c.GetColorPalette().GetSeriesColor(seriesIndex),
+		DotColor:    strokeColor,
+		StrokeColor: strokeColor,
 		StrokeWidth: DefaultSeriesLineWidth,
 		Font:        c.GetFont(),
 		FontSize:    DefaultFontSize,
@@ -542,9 +524,9 @@ func (c Chart) styleDefaultsSeries(seriesIndex int) Style {
 func (c Chart) styleDefaultsAxes() Style {
 	return Style{
 		Font:        c.GetFont(),
-		FontColor:   c.GetColorPalette().TextColor(),
+		FontColor:   DefaultAxisColor,
 		FontSize:    DefaultAxisFontSize,
-		StrokeColor: c.GetColorPalette().AxisStrokeColor(),
+		StrokeColor: DefaultAxisColor,
 		StrokeWidth: DefaultAxisLineWidth,
 	}
 }
@@ -555,14 +537,6 @@ func (c Chart) styleDefaultsElements() Style {
 	}
 }
 
-// GetColorPalette returns the color palette for the chart.
-func (c Chart) GetColorPalette() ColorPalette {
-	if c.ColorPalette != nil {
-		return c.ColorPalette
-	}
-	return DefaultColorPalette
-}
-
 // Box returns the chart bounds as a box.
 func (c Chart) Box() Box {
 	dpr := c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)

chart_test.go

@@ -8,57 +8,57 @@ import (
 	"testing"
 	"time"
 
-	"git.smarteching.com/zeni/go-chart/v2/drawing"
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	"github.com/blendlabs/go-assert"
+	"github.com/wcharczuk/go-chart/drawing"
 )
 
 func TestChartGetDPI(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	unset := Chart{}
-	testutil.AssertEqual(t, DefaultDPI, unset.GetDPI())
-	testutil.AssertEqual(t, 192, unset.GetDPI(192))
+	assert.Equal(DefaultDPI, unset.GetDPI())
+	assert.Equal(192, unset.GetDPI(192))
 
 	set := Chart{DPI: 128}
-	testutil.AssertEqual(t, 128, set.GetDPI())
-	testutil.AssertEqual(t, 128, set.GetDPI(192))
+	assert.Equal(128, set.GetDPI())
+	assert.Equal(128, set.GetDPI(192))
 }
 
 func TestChartGetFont(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	f, err := GetDefaultFont()
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 
 	unset := Chart{}
-	testutil.AssertNil(t, unset.GetFont())
+	assert.Nil(unset.GetFont())
 
 	set := Chart{Font: f}
-	testutil.AssertNotNil(t, set.GetFont())
+	assert.NotNil(set.GetFont())
 }
 
 func TestChartGetWidth(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	unset := Chart{}
-	testutil.AssertEqual(t, DefaultChartWidth, unset.GetWidth())
+	assert.Equal(DefaultChartWidth, unset.GetWidth())
 
 	set := Chart{Width: DefaultChartWidth + 10}
-	testutil.AssertEqual(t, DefaultChartWidth+10, set.GetWidth())
+	assert.Equal(DefaultChartWidth+10, set.GetWidth())
 }
 
 func TestChartGetHeight(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	unset := Chart{}
-	testutil.AssertEqual(t, DefaultChartHeight, unset.GetHeight())
+	assert.Equal(DefaultChartHeight, unset.GetHeight())
 
 	set := Chart{Height: DefaultChartHeight + 10}
-	testutil.AssertEqual(t, DefaultChartHeight+10, set.GetHeight())
+	assert.Equal(DefaultChartHeight+10, set.GetHeight())
 }
 
 func TestChartGetRanges(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		Series: []Series{
@@ -79,14 +79,14 @@ func TestChartGetRanges(t *testing.T) {
 	}
 
 	xrange, yrange, yrangeAlt := c.getRanges()
-	testutil.AssertEqual(t, -2.0, xrange.GetMin())
-	testutil.AssertEqual(t, 5.0, xrange.GetMax())
+	assert.Equal(-2.0, xrange.GetMin())
+	assert.Equal(5.0, xrange.GetMax())
 
-	testutil.AssertEqual(t, -2.1, yrange.GetMin())
-	testutil.AssertEqual(t, 4.5, yrange.GetMax())
+	assert.Equal(-2.1, yrange.GetMin())
+	assert.Equal(4.5, yrange.GetMax())
 
-	testutil.AssertEqual(t, 10.0, yrangeAlt.GetMin())
-	testutil.AssertEqual(t, 14.0, yrangeAlt.GetMax())
+	assert.Equal(10.0, yrangeAlt.GetMin())
+	assert.Equal(14.0, yrangeAlt.GetMax())
 
 	cSet := Chart{
 		XAxis: XAxis{
@@ -116,18 +116,18 @@ func TestChartGetRanges(t *testing.T) {
 	}
 
 	xr2, yr2, yra2 := cSet.getRanges()
-	testutil.AssertEqual(t, 9.8, xr2.GetMin())
-	testutil.AssertEqual(t, 19.8, xr2.GetMax())
+	assert.Equal(9.8, xr2.GetMin())
+	assert.Equal(19.8, xr2.GetMax())
 
-	testutil.AssertEqual(t, 9.9, yr2.GetMin())
-	testutil.AssertEqual(t, 19.9, yr2.GetMax())
+	assert.Equal(9.9, yr2.GetMin())
+	assert.Equal(19.9, yr2.GetMax())
 
-	testutil.AssertEqual(t, 9.7, yra2.GetMin())
-	testutil.AssertEqual(t, 19.7, yra2.GetMax())
+	assert.Equal(9.7, yra2.GetMin())
+	assert.Equal(19.7, yra2.GetMax())
 }
 
 func TestChartGetRangesUseTicks(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	// this test asserts that ticks should supercede manual ranges when generating the overall ranges.
 
@@ -155,15 +155,15 @@ func TestChartGetRangesUseTicks(t *testing.T) {
 	}
 
 	xr, yr, yar := c.getRanges()
-	testutil.AssertEqual(t, -2.0, xr.GetMin())
-	testutil.AssertEqual(t, 2.0, xr.GetMax())
-	testutil.AssertEqual(t, 0.0, yr.GetMin())
-	testutil.AssertEqual(t, 5.0, yr.GetMax())
-	testutil.AssertTrue(t, yar.IsZero(), yar.String())
+	assert.Equal(-2.0, xr.GetMin())
+	assert.Equal(2.0, xr.GetMax())
+	assert.Equal(0.0, yr.GetMin())
+	assert.Equal(5.0, yr.GetMax())
+	assert.True(yar.IsZero(), yar.String())
 }
 
 func TestChartGetRangesUseUserRanges(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		YAxis: YAxis{
@@ -181,15 +181,15 @@ func TestChartGetRangesUseUserRanges(t *testing.T) {
 	}
 
 	xr, yr, yar := c.getRanges()
-	testutil.AssertEqual(t, -2.0, xr.GetMin())
-	testutil.AssertEqual(t, 2.0, xr.GetMax())
-	testutil.AssertEqual(t, -5.0, yr.GetMin())
-	testutil.AssertEqual(t, 5.0, yr.GetMax())
-	testutil.AssertTrue(t, yar.IsZero(), yar.String())
+	assert.Equal(-2.0, xr.GetMin())
+	assert.Equal(2.0, xr.GetMax())
+	assert.Equal(-5.0, yr.GetMin())
+	assert.Equal(5.0, yr.GetMax())
+	assert.True(yar.IsZero(), yar.String())
 }
 
 func TestChartGetBackgroundStyle(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		Background: Style{
@@ -198,11 +198,11 @@ func TestChartGetBackgroundStyle(t *testing.T) {
 	}
 
 	bs := c.getBackgroundStyle()
-	testutil.AssertEqual(t, bs.FillColor.String(), drawing.ColorBlack.String())
+	assert.Equal(bs.FillColor.String(), drawing.ColorBlack.String())
 }
 
 func TestChartGetCanvasStyle(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		Canvas: Style{
@@ -211,19 +211,19 @@ func TestChartGetCanvasStyle(t *testing.T) {
 	}
 
 	bs := c.getCanvasStyle()
-	testutil.AssertEqual(t, bs.FillColor.String(), drawing.ColorBlack.String())
+	assert.Equal(bs.FillColor.String(), drawing.ColorBlack.String())
 }
 
 func TestChartGetDefaultCanvasBox(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{}
 	canvasBoxDefault := c.getDefaultCanvasBox()
-	testutil.AssertFalse(t, canvasBoxDefault.IsZero())
-	testutil.AssertEqual(t, DefaultBackgroundPadding.Top, canvasBoxDefault.Top)
-	testutil.AssertEqual(t, DefaultBackgroundPadding.Left, canvasBoxDefault.Left)
-	testutil.AssertEqual(t, c.GetWidth()-DefaultBackgroundPadding.Right, canvasBoxDefault.Right)
-	testutil.AssertEqual(t, c.GetHeight()-DefaultBackgroundPadding.Bottom, canvasBoxDefault.Bottom)
+	assert.False(canvasBoxDefault.IsZero())
+	assert.Equal(DefaultBackgroundPadding.Top, canvasBoxDefault.Top)
+	assert.Equal(DefaultBackgroundPadding.Left, canvasBoxDefault.Left)
+	assert.Equal(c.GetWidth()-DefaultBackgroundPadding.Right, canvasBoxDefault.Right)
+	assert.Equal(c.GetHeight()-DefaultBackgroundPadding.Bottom, canvasBoxDefault.Bottom)
 
 	custom := Chart{
 		Background: Style{
@@ -236,15 +236,15 @@ func TestChartGetDefaultCanvasBox(t *testing.T) {
 		},
 	}
 	canvasBoxCustom := custom.getDefaultCanvasBox()
-	testutil.AssertFalse(t, canvasBoxCustom.IsZero())
-	testutil.AssertEqual(t, DefaultBackgroundPadding.Top+1, canvasBoxCustom.Top)
-	testutil.AssertEqual(t, DefaultBackgroundPadding.Left+1, canvasBoxCustom.Left)
-	testutil.AssertEqual(t, c.GetWidth()-(DefaultBackgroundPadding.Right+1), canvasBoxCustom.Right)
-	testutil.AssertEqual(t, c.GetHeight()-(DefaultBackgroundPadding.Bottom+1), canvasBoxCustom.Bottom)
+	assert.False(canvasBoxCustom.IsZero())
+	assert.Equal(DefaultBackgroundPadding.Top+1, canvasBoxCustom.Top)
+	assert.Equal(DefaultBackgroundPadding.Left+1, canvasBoxCustom.Left)
+	assert.Equal(c.GetWidth()-(DefaultBackgroundPadding.Right+1), canvasBoxCustom.Right)
+	assert.Equal(c.GetHeight()-(DefaultBackgroundPadding.Bottom+1), canvasBoxCustom.Bottom)
 }
 
 func TestChartGetValueFormatters(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		Series: []Series{
@@ -265,95 +265,90 @@ func TestChartGetValueFormatters(t *testing.T) {
 	}
 
 	dxf, dyf, dyaf := c.getValueFormatters()
-	testutil.AssertNotNil(t, dxf)
-	testutil.AssertNotNil(t, dyf)
-	testutil.AssertNotNil(t, dyaf)
+	assert.NotNil(dxf)
+	assert.NotNil(dyf)
+	assert.NotNil(dyaf)
 }
 
 func TestChartHasAxes(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
-	testutil.AssertTrue(t, Chart{}.hasAxes())
-	testutil.AssertFalse(t, Chart{XAxis: XAxis{Style: Hidden()}, YAxis: YAxis{Style: Hidden()}, YAxisSecondary: YAxis{Style: Hidden()}}.hasAxes())
+	assert.False(Chart{}.hasAxes())
 
 	x := Chart{
 		XAxis: XAxis{
-			Style: Hidden(),
-		},
-		YAxis: YAxis{
-			Style: Shown(),
-		},
-		YAxisSecondary: YAxis{
-			Style: Hidden(),
+			Style: Style{
+				Show: true,
+			},
 		},
 	}
-	testutil.AssertTrue(t, x.hasAxes())
+	assert.True(x.hasAxes())
 
 	y := Chart{
-		XAxis: XAxis{
-			Style: Shown(),
-		},
 		YAxis: YAxis{
-			Style: Hidden(),
-		},
-		YAxisSecondary: YAxis{
-			Style: Hidden(),
+			Style: Style{
+				Show: true,
+			},
 		},
 	}
-	testutil.AssertTrue(t, y.hasAxes())
+	assert.True(y.hasAxes())
 
 	ya := Chart{
-		XAxis: XAxis{
-			Style: Hidden(),
-		},
-		YAxis: YAxis{
-			Style: Hidden(),
-		},
 		YAxisSecondary: YAxis{
-			Style: Shown(),
+			Style: Style{
+				Show: true,
+			},
 		},
 	}
-	testutil.AssertTrue(t, ya.hasAxes())
+	assert.True(ya.hasAxes())
 }
 
 func TestChartGetAxesTicks(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	r, err := PNG(1024, 1024)
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 
 	c := Chart{
 		XAxis: XAxis{
+			Style: Style{Show: true},
 			Range: &ContinuousRange{Min: 9.8, Max: 19.8},
 		},
 		YAxis: YAxis{
+			Style: Style{Show: true},
 			Range: &ContinuousRange{Min: 9.9, Max: 19.9},
 		},
 		YAxisSecondary: YAxis{
+			Style: Style{Show: true},
 			Range: &ContinuousRange{Min: 9.7, Max: 19.7},
 		},
 	}
 	xr, yr, yar := c.getRanges()
 
 	xt, yt, yat := c.getAxesTicks(r, xr, yr, yar, FloatValueFormatter, FloatValueFormatter, FloatValueFormatter)
-	testutil.AssertNotEmpty(t, xt)
-	testutil.AssertNotEmpty(t, yt)
-	testutil.AssertNotEmpty(t, yat)
+	assert.NotEmpty(xt)
+	assert.NotEmpty(yt)
+	assert.NotEmpty(yat)
 }
 
 func TestChartSingleSeries(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 	now := time.Now()
 	c := Chart{
-		Title:  "Hello!",
-		Width:  1024,
-		Height: 400,
+		Title:      "Hello!",
+		TitleStyle: StyleShow(),
+		Width:      1024,
+		Height:     400,
 		YAxis: YAxis{
+			Style: StyleShow(),
 			Range: &ContinuousRange{
 				Min: 0.0,
 				Max: 4.0,
 			},
 		},
+		XAxis: XAxis{
+			Style: StyleShow(),
+		},
 		Series: []Series{
 			TimeSeries{
 				Name:    "goog",
@@ -365,11 +360,11 @@ func TestChartSingleSeries(t *testing.T) {
 
 	buffer := bytes.NewBuffer([]byte{})
 	c.Render(PNG, buffer)
-	testutil.AssertNotEmpty(t, buffer.Bytes())
+	assert.NotEmpty(buffer.Bytes())
 }
 
 func TestChartRegressionBadRanges(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		Series: []Series{
@@ -381,11 +376,11 @@ func TestChartRegressionBadRanges(t *testing.T) {
 	}
 	buffer := bytes.NewBuffer([]byte{})
 	c.Render(PNG, buffer)
-	testutil.AssertTrue(t, true, "Render needs to finish.")
+	assert.True(true, "Render needs to finish.")
 }
 
 func TestChartRegressionBadRangesByUser(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		YAxis: YAxis{
@@ -396,43 +391,43 @@ func TestChartRegressionBadRangesByUser(t *testing.T) {
 		},
 		Series: []Series{
 			ContinuousSeries{
-				XValues: LinearRange(1.0, 10.0),
-				YValues: LinearRange(1.0, 10.0),
+				XValues: Sequence.Float64(1.0, 10.0),
+				YValues: Sequence.Float64(1.0, 10.0),
 			},
 		},
 	}
 	buffer := bytes.NewBuffer([]byte{})
 	c.Render(PNG, buffer)
-	testutil.AssertTrue(t, true, "Render needs to finish.")
+	assert.True(true, "Render needs to finish.")
 }
 
 func TestChartValidatesSeries(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		Series: []Series{
 			ContinuousSeries{
-				XValues: LinearRange(1.0, 10.0),
-				YValues: LinearRange(1.0, 10.0),
+				XValues: Sequence.Float64(1.0, 10.0),
+				YValues: Sequence.Float64(1.0, 10.0),
 			},
 		},
 	}
 
-	testutil.AssertNil(t, c.validateSeries())
+	assert.Nil(c.validateSeries())
 
 	c = Chart{
 		Series: []Series{
 			ContinuousSeries{
-				XValues: LinearRange(1.0, 10.0),
+				XValues: Sequence.Float64(1.0, 10.0),
 			},
 		},
 	}
 
-	testutil.AssertNotNil(t, c.validateSeries())
+	assert.NotNil(c.validateSeries())
 }
 
 func TestChartCheckRanges(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		Series: []Series{
@@ -444,11 +439,27 @@ func TestChartCheckRanges(t *testing.T) {
 	}
 
 	xr, yr, yra := c.getRanges()
-	testutil.AssertNil(t, c.checkRanges(xr, yr, yra))
+	assert.Nil(c.checkRanges(xr, yr, yra))
+}
+
+func TestChartCheckRangesFailure(t *testing.T) {
+	assert := assert.New(t)
+
+	c := Chart{
+		Series: []Series{
+			ContinuousSeries{
+				XValues: []float64{1.0, 2.0},
+				YValues: []float64{3.14, 3.14},
+			},
+		},
+	}
+
+	xr, yr, yra := c.getRanges()
+	assert.NotNil(c.checkRanges(xr, yr, yra))
 }
 
 func TestChartCheckRangesWithRanges(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	c := Chart{
 		XAxis: XAxis{
@@ -472,7 +483,7 @@ func TestChartCheckRangesWithRanges(t *testing.T) {
 	}
 
 	xr, yr, yra := c.getRanges()
-	testutil.AssertNil(t, c.checkRanges(xr, yr, yra))
+	assert.Nil(c.checkRanges(xr, yr, yra))
 }
 
 func at(i image.Image, x, y int) drawing.Color {
@@ -480,115 +491,85 @@ func at(i image.Image, x, y int) drawing.Color {
 }
 
 func TestChartE2ELine(t *testing.T) {
-	// replaced new assertions helper
-
-	c := Chart{
-		Height:         50,
-		Width:          50,
-		TitleStyle:     Hidden(),
-		XAxis:          HideXAxis(),
-		YAxis:          HideYAxis(),
-		YAxisSecondary: HideYAxis(),
-		Canvas: Style{
-			Padding: BoxZero,
-		},
-		Background: Style{
-			Padding: BoxZero,
-		},
-		Series: []Series{
-			ContinuousSeries{
-				XValues: LinearRangeWithStep(0, 4, 1),
-				YValues: LinearRangeWithStep(0, 4, 1),
-			},
-		},
-	}
-
-	var buffer = &bytes.Buffer{}
-	err := c.Render(PNG, buffer)
-	testutil.AssertNil(t, err)
-
-	// do color tests ...
-
-	i, err := png.Decode(buffer)
-	testutil.AssertNil(t, err)
-
-	// test the bottom and top of the line
-	testutil.AssertEqual(t, drawing.ColorWhite, at(i, 0, 0))
-	testutil.AssertEqual(t, drawing.ColorWhite, at(i, 49, 49))
-
-	// test a line mid point
-	defaultSeriesColor := GetDefaultColor(0)
-	testutil.AssertEqual(t, defaultSeriesColor, at(i, 0, 49))
-	testutil.AssertEqual(t, defaultSeriesColor, at(i, 49, 0))
-	testutil.AssertEqual(t, drawing.ColorFromHex("bddbf6"), at(i, 24, 24))
-}
-
-func TestChartE2ELineWithFill(t *testing.T) {
-	// replaced new assertions helper
-
-	logBuffer := new(bytes.Buffer)
+	assert := assert.New(t)
 
 	c := Chart{
 		Height: 50,
 		Width:  50,
 		Canvas: Style{
-			Padding: BoxZero,
+			Padding: Box{IsSet: true},
 		},
 		Background: Style{
-			Padding: BoxZero,
+			Padding: Box{IsSet: true},
 		},
-		TitleStyle:     Hidden(),
-		XAxis:          HideXAxis(),
-		YAxis:          HideYAxis(),
-		YAxisSecondary: HideYAxis(),
 		Series: []Series{
 			ContinuousSeries{
-				Style: Style{
-					StrokeColor: drawing.ColorBlue,
-					FillColor:   drawing.ColorRed,
-				},
-				XValues: LinearRangeWithStep(0, 4, 1),
-				YValues: LinearRangeWithStep(0, 4, 1),
+				XValues: Sequence.Float64(0, 4, 1),
+				YValues: Sequence.Float64(0, 4, 1),
 			},
 		},
-		Log: NewLogger(OptLoggerStdout(logBuffer), OptLoggerStderr(logBuffer)),
 	}
 
-	testutil.AssertEqual(t, 5, len(c.Series[0].(ContinuousSeries).XValues))
-	testutil.AssertEqual(t, 5, len(c.Series[0].(ContinuousSeries).YValues))
-
 	var buffer = &bytes.Buffer{}
 	err := c.Render(PNG, buffer)
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
+
+	// do color tests ...
 
 	i, err := png.Decode(buffer)
-	testutil.AssertNil(t, err)
+	assert.Nil(err)
 
 	// test the bottom and top of the line
-	testutil.AssertEqual(t, drawing.ColorWhite, at(i, 0, 0))
-	testutil.AssertEqual(t, drawing.ColorRed, at(i, 49, 49))
+	assert.Equal(drawing.ColorWhite, at(i, 0, 0))
+	assert.Equal(drawing.ColorWhite, at(i, 49, 49))
 
 	// test a line mid point
-	defaultSeriesColor := drawing.ColorBlue
-	testutil.AssertEqual(t, defaultSeriesColor, at(i, 0, 49))
-	testutil.AssertEqual(t, defaultSeriesColor, at(i, 49, 0))
+	defaultSeriesColor := GetDefaultColor(0)
+	assert.Equal(defaultSeriesColor, at(i, 0, 49))
+	assert.Equal(defaultSeriesColor, at(i, 49, 0))
+	assert.Equal(drawing.ColorFromHex("bddbf6"), at(i, 24, 24))
 }
 
-func Test_Chart_cve(t *testing.T) {
-	poc := StackedBarChart{
-		Title: "poc",
-		Bars: []StackedBar{
-			{
-				Name: "11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111",
-				Values: []Value{
-					{Value: 1, Label: "infinite"},
-					{Value: 1, Label: "loop"},
+func TestChartE2ELineWithFill(t *testing.T) {
+	assert := assert.New(t)
+
+	c := Chart{
+		Height: 50,
+		Width:  50,
+		Canvas: Style{
+			Padding: Box{IsSet: true},
+		},
+		Background: Style{
+			Padding: Box{IsSet: true},
+		},
+		Series: []Series{
+			ContinuousSeries{
+				Style: Style{
+					Show:        true,
+					StrokeColor: drawing.ColorBlue,
+					FillColor:   drawing.ColorRed,
 				},
+				XValues: Sequence.Float64(0, 4, 1),
+				YValues: Sequence.Float64(0, 4, 1),
 			},
 		},
 	}
 
-	var imgContent bytes.Buffer
-	err := poc.Render(PNG, &imgContent)
-	testutil.AssertNotNil(t, err)
+	var buffer = &bytes.Buffer{}
+	err := c.Render(PNG, buffer)
+	assert.Nil(err)
+
+	// do color tests ...
+
+	i, err := png.Decode(buffer)
+	assert.Nil(err)
+
+	// test the bottom and top of the line
+	assert.Equal(drawing.ColorWhite, at(i, 0, 0))
+	assert.Equal(drawing.ColorRed, at(i, 49, 49))
+
+	// test a line mid point
+	defaultSeriesColor := drawing.ColorBlue
+	assert.Equal(defaultSeriesColor, at(i, 0, 49))
+	assert.Equal(defaultSeriesColor, at(i, 49, 0))
 }

cmd/chart/main.go

@@ -1,148 +0,0 @@
-package main
-
-import (
-	"flag"
-	"fmt"
-	"io/ioutil"
-	"os"
-	"strings"
-
-	"git.smarteching.com/zeni/go-chart/v2"
-)
-
-var (
-	outputPath = flag.String("output", "", "The output file")
-
-	inputFormat = flag.String("format", "csv", "The input format, either 'csv' or 'tsv' (defaults to 'csv')")
-	inputPath   = flag.String("f", "", "The input file")
-	reverse     = flag.Bool("reverse", false, "If we should reverse the inputs")
-
-	hideLegend     = flag.Bool("hide-legend", false, "If we should omit the chart legend")
-	hideSMA        = flag.Bool("hide-sma", false, "If we should omit simple moving average")
-	hideLinreg     = flag.Bool("hide-linreg", false, "If we should omit linear regressions")
-	hideLastValues = flag.Bool("hide-last-values", false, "If we should omit last values")
-)
-
-func main() {
-	flag.Parse()
-	log := chart.NewLogger()
-
-	var rawData []byte
-	var err error
-	if *inputPath != "" {
-		if *inputPath == "-" {
-			rawData, err = ioutil.ReadAll(os.Stdin)
-			if err != nil {
-				log.FatalErr(err)
-			}
-		} else {
-			rawData, err = ioutil.ReadFile(*inputPath)
-			if err != nil {
-				log.FatalErr(err)
-			}
-		}
-	} else if len(flag.Args()) > 0 {
-		rawData = []byte(flag.Args()[0])
-	} else {
-		flag.Usage()
-		os.Exit(1)
-	}
-
-	var parts []string
-	switch *inputFormat {
-	case "csv":
-		parts = chart.SplitCSV(string(rawData))
-	case "tsv":
-		parts = strings.Split(string(rawData), "\t")
-	default:
-		log.FatalErr(fmt.Errorf("invalid format; must be 'csv' or 'tsv'"))
-	}
-
-	yvalues, err := chart.ParseFloats(parts...)
-	if err != nil {
-		log.FatalErr(err)
-	}
-
-	if *reverse {
-		yvalues = chart.ValueSequence(yvalues...).Reverse().Values()
-	}
-
-	var series []chart.Series
-	mainSeries := chart.ContinuousSeries{
-		Name:    "Values",
-		XValues: chart.LinearRange(1, float64(len(yvalues))),
-		YValues: yvalues,
-	}
-	series = append(series, mainSeries)
-
-	smaSeries := &chart.SMASeries{
-		Name: "SMA",
-		Style: chart.Style{
-			Hidden:          *hideSMA,
-			StrokeColor:     chart.ColorRed,
-			StrokeDashArray: []float64{5.0, 5.0},
-		},
-		InnerSeries: mainSeries,
-	}
-	series = append(series, smaSeries)
-
-	linRegSeries := &chart.LinearRegressionSeries{
-		Name: "Values - Lin. Reg.",
-		Style: chart.Style{
-			Hidden: *hideLinreg,
-		},
-		InnerSeries: mainSeries,
-	}
-	series = append(series, linRegSeries)
-
-	mainLastValue := chart.LastValueAnnotationSeries(mainSeries)
-	mainLastValue.Style = chart.Style{
-		Hidden: *hideLastValues,
-	}
-	series = append(series, mainLastValue)
-
-	linregLastValue := chart.LastValueAnnotationSeries(linRegSeries)
-	linregLastValue.Style = chart.Style{
-		Hidden: (*hideLastValues || *hideLinreg),
-	}
-	series = append(series, linregLastValue)
-
-	smaLastValue := chart.LastValueAnnotationSeries(smaSeries)
-	smaLastValue.Style = chart.Style{
-		Hidden: (*hideLastValues || *hideSMA),
-	}
-	series = append(series, smaLastValue)
-
-	graph := chart.Chart{
-		Background: chart.Style{
-			Padding: chart.Box{
-				Top: 50,
-			},
-		},
-		Series: series,
-	}
-
-	if !*hideLegend {
-		graph.Elements = []chart.Renderable{chart.LegendThin(&graph)}
-	}
-
-	var output *os.File
-	if *outputPath != "" {
-		output, err = os.Create(*outputPath)
-		if err != nil {
-			log.FatalErr(err)
-		}
-	} else {
-		output, err = ioutil.TempFile("", "*.png")
-		if err != nil {
-			log.FatalErr(err)
-		}
-	}
-
-	if err := graph.Render(chart.PNG, output); err != nil {
-		log.FatalErr(err)
-	}
-
-	fmt.Fprintln(os.Stdout, output.Name())
-	os.Exit(0)
-}

colors.go

@@ -1,184 +0,0 @@
-package chart
-
-import "git.smarteching.com/zeni/go-chart/v2/drawing"
-
-var (
-	// ColorWhite is white.
-	ColorWhite = drawing.Color{R: 255, G: 255, B: 255, A: 255}
-	// ColorBlue is the basic theme blue color.
-	ColorBlue = drawing.Color{R: 0, G: 116, B: 217, A: 255}
-	// ColorCyan is the basic theme cyan color.
-	ColorCyan = drawing.Color{R: 0, G: 217, B: 210, A: 255}
-	// ColorGreen is the basic theme green color.
-	ColorGreen = drawing.Color{R: 0, G: 217, B: 101, A: 255}
-	// ColorRed is the basic theme red color.
-	ColorRed = drawing.Color{R: 217, G: 0, B: 116, A: 255}
-	// ColorOrange is the basic theme orange color.
-	ColorOrange = drawing.Color{R: 217, G: 101, B: 0, A: 255}
-	// ColorYellow is the basic theme yellow color.
-	ColorYellow = drawing.Color{R: 217, G: 210, B: 0, A: 255}
-	// ColorBlack is the basic theme black color.
-	ColorBlack = drawing.Color{R: 51, G: 51, B: 51, A: 255}
-	// ColorLightGray is the basic theme light gray color.
-	ColorLightGray = drawing.Color{R: 239, G: 239, B: 239, A: 255}
-
-	// ColorAlternateBlue is a alternate theme color.
-	ColorAlternateBlue = drawing.Color{R: 106, G: 195, B: 203, A: 255}
-	// ColorAlternateGreen is a alternate theme color.
-	ColorAlternateGreen = drawing.Color{R: 42, G: 190, B: 137, A: 255}
-	// ColorAlternateGray is a alternate theme color.
-	ColorAlternateGray = drawing.Color{R: 110, G: 128, B: 139, A: 255}
-	// ColorAlternateYellow is a alternate theme color.
-	ColorAlternateYellow = drawing.Color{R: 240, G: 174, B: 90, A: 255}
-	// ColorAlternateLightGray is a alternate theme color.
-	ColorAlternateLightGray = drawing.Color{R: 187, G: 190, B: 191, A: 255}
-
-	// ColorTransparent is a transparent (alpha zero) color.
-	ColorTransparent = drawing.Color{R: 1, G: 1, B: 1, A: 0}
-)
-
-var (
-	// DefaultBackgroundColor is the default chart background color.
-	// It is equivalent to css color:white.
-	DefaultBackgroundColor = ColorWhite
-	// DefaultBackgroundStrokeColor is the default chart border color.
-	// It is equivalent to color:white.
-	DefaultBackgroundStrokeColor = ColorWhite
-	// DefaultCanvasColor is the default chart canvas color.
-	// It is equivalent to css color:white.
-	DefaultCanvasColor = ColorWhite
-	// DefaultCanvasStrokeColor is the default chart canvas stroke color.
-	// It is equivalent to css color:white.
-	DefaultCanvasStrokeColor = ColorWhite
-	// DefaultTextColor is the default chart text color.
-	// It is equivalent to #333333.
-	DefaultTextColor = ColorBlack
-	// DefaultAxisColor is the default chart axis line color.
-	// It is equivalent to #333333.
-	DefaultAxisColor = ColorBlack
-	// DefaultStrokeColor is the default chart border color.
-	// It is equivalent to #efefef.
-	DefaultStrokeColor = ColorLightGray
-	// DefaultFillColor is the default fill color.
-	// It is equivalent to #0074d9.
-	DefaultFillColor = ColorBlue
-	// DefaultAnnotationFillColor is the default annotation background color.
-	DefaultAnnotationFillColor = ColorWhite
-	// DefaultGridLineColor is the default grid line color.
-	DefaultGridLineColor = ColorLightGray
-)
-
-var (
-	// DefaultColors are a couple default series colors.
-	DefaultColors = []drawing.Color{
-		ColorBlue,
-		ColorGreen,
-		ColorRed,
-		ColorCyan,
-		ColorOrange,
-	}
-
-	// DefaultAlternateColors are a couple alternate colors.
-	DefaultAlternateColors = []drawing.Color{
-		ColorAlternateBlue,
-		ColorAlternateGreen,
-		ColorAlternateGray,
-		ColorAlternateYellow,
-		ColorBlue,
-		ColorGreen,
-		ColorRed,
-		ColorCyan,
-		ColorOrange,
-	}
-)
-
-// GetDefaultColor returns a color from the default list by index.
-// NOTE: the index will wrap around (using a modulo).
-func GetDefaultColor(index int) drawing.Color {
-	finalIndex := index % len(DefaultColors)
-	return DefaultColors[finalIndex]
-}
-
-// GetAlternateColor returns a color from the default list by index.
-// NOTE: the index will wrap around (using a modulo).
-func GetAlternateColor(index int) drawing.Color {
-	finalIndex := index % len(DefaultAlternateColors)
-	return DefaultAlternateColors[finalIndex]
-}
-
-// ColorPalette is a set of colors that.
-type ColorPalette interface {
-	BackgroundColor() drawing.Color
-	BackgroundStrokeColor() drawing.Color
-	CanvasColor() drawing.Color
-	CanvasStrokeColor() drawing.Color
-	AxisStrokeColor() drawing.Color
-	TextColor() drawing.Color
-	GetSeriesColor(index int) drawing.Color
-}
-
-// DefaultColorPalette represents the default palatte.
-var DefaultColorPalette defaultColorPalette
-
-type defaultColorPalette struct{}
-
-func (dp defaultColorPalette) BackgroundColor() drawing.Color {
-	return DefaultBackgroundColor
-}
-
-func (dp defaultColorPalette) BackgroundStrokeColor() drawing.Color {
-	return DefaultBackgroundStrokeColor
-}
-
-func (dp defaultColorPalette) CanvasColor() drawing.Color {
-	return DefaultCanvasColor
-}
-
-func (dp defaultColorPalette) CanvasStrokeColor() drawing.Color {
-	return DefaultCanvasStrokeColor
-}
-
-func (dp defaultColorPalette) AxisStrokeColor() drawing.Color {
-	return DefaultAxisColor
-}
-
-func (dp defaultColorPalette) TextColor() drawing.Color {
-	return DefaultTextColor
-}
-
-func (dp defaultColorPalette) GetSeriesColor(index int) drawing.Color {
-	return GetDefaultColor(index)
-}
-
-// AlternateColorPalette represents the default palatte.
-var AlternateColorPalette alternateColorPalette
-
-type alternateColorPalette struct{}
-
-func (ap alternateColorPalette) BackgroundColor() drawing.Color {
-	return DefaultBackgroundColor
-}
-
-func (ap alternateColorPalette) BackgroundStrokeColor() drawing.Color {
-	return DefaultBackgroundStrokeColor
-}
-
-func (ap alternateColorPalette) CanvasColor() drawing.Color {
-	return DefaultCanvasColor
-}
-
-func (ap alternateColorPalette) CanvasStrokeColor() drawing.Color {
-	return DefaultCanvasStrokeColor
-}
-
-func (ap alternateColorPalette) AxisStrokeColor() drawing.Color {
-	return DefaultAxisColor
-}
-
-func (ap alternateColorPalette) TextColor() drawing.Color {
-	return DefaultTextColor
-}
-
-func (ap alternateColorPalette) GetSeriesColor(index int) drawing.Color {
-	return GetAlternateColor(index)
-}

concat_series.go

@@ -7,7 +7,7 @@ type ConcatSeries []Series
 func (cs ConcatSeries) Len() int {
 	total := 0
 	for _, s := range cs {
-		if typed, isValuesProvider := s.(ValuesProvider); isValuesProvider {
+		if typed, isValueProvider := s.(ValueProvider); isValueProvider {
 			total += typed.Len()
 		}
 	}
@@ -19,10 +19,10 @@ func (cs ConcatSeries) Len() int {
 func (cs ConcatSeries) GetValue(index int) (x, y float64) {
 	cursor := 0
 	for _, s := range cs {
-		if typed, isValuesProvider := s.(ValuesProvider); isValuesProvider {
+		if typed, isValueProvider := s.(ValueProvider); isValueProvider {
 			len := typed.Len()
 			if index < cursor+len {
-				x, y = typed.GetValues(index - cursor) //FENCEPOSTS.
+				x, y = typed.GetValue(index - cursor) //FENCEPOSTS.
 				return
 			}
 			cursor += typed.Len()

concat_series_test.go

@@ -3,39 +3,39 @@ package chart
 import (
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	assert "github.com/blendlabs/go-assert"
 )
 
 func TestConcatSeries(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	s1 := ContinuousSeries{
-		XValues: LinearRange(1.0, 10.0),
-		YValues: LinearRange(1.0, 10.0),
+		XValues: Sequence.Float64(1.0, 10.0),
+		YValues: Sequence.Float64(1.0, 10.0),
 	}
 
 	s2 := ContinuousSeries{
-		XValues: LinearRange(11, 20.0),
-		YValues: LinearRange(10.0, 1.0),
+		XValues: Sequence.Float64(11, 20.0),
+		YValues: Sequence.Float64(10.0, 1.0),
 	}
 
 	s3 := ContinuousSeries{
-		XValues: LinearRange(21, 30.0),
-		YValues: LinearRange(1.0, 10.0),
+		XValues: Sequence.Float64(21, 30.0),
+		YValues: Sequence.Float64(1.0, 10.0),
 	}
 
 	cs := ConcatSeries([]Series{s1, s2, s3})
-	testutil.AssertEqual(t, 30, cs.Len())
+	assert.Equal(30, cs.Len())
 
 	x0, y0 := cs.GetValue(0)
-	testutil.AssertEqual(t, 1.0, x0)
-	testutil.AssertEqual(t, 1.0, y0)
+	assert.Equal(1.0, x0)
+	assert.Equal(1.0, y0)
 
 	xm, ym := cs.GetValue(19)
-	testutil.AssertEqual(t, 20.0, xm)
-	testutil.AssertEqual(t, 1.0, ym)
+	assert.Equal(20.0, xm)
+	assert.Equal(1.0, ym)
 
 	xn, yn := cs.GetValue(29)
-	testutil.AssertEqual(t, 30.0, xn)
-	testutil.AssertEqual(t, 10.0, yn)
+	assert.Equal(30.0, xn)
+	assert.Equal(10.0, yn)
 }

continuous_range.go

@@ -62,9 +62,6 @@ func (r *ContinuousRange) SetDomain(domain int) {
 
 // String returns a simple string for the ContinuousRange.
 func (r ContinuousRange) String() string {
-	if r.GetDelta() == 0 {
-		return "ContinuousRange [empty]"
-	}
 	return fmt.Sprintf("ContinuousRange [%.2f,%.2f] => %d", r.Min, r.Max, r.Domain)
 }
 

continuous_range_test.go

@@ -3,20 +3,20 @@ package chart
 import (
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	"github.com/blendlabs/go-assert"
 )
 
 func TestRangeTranslate(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 	values := []float64{1.0, 2.0, 2.5, 2.7, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0}
 	r := ContinuousRange{Domain: 1000}
-	r.Min, r.Max = MinMax(values...)
+	r.Min, r.Max = Math.MinAndMax(values...)
 
 	// delta = ~7.0
 	// value = ~5.0
 	// domain = ~1000
 	// 5/8 * 1000 ~=
-	testutil.AssertEqual(t, 0, r.Translate(1.0))
-	testutil.AssertEqual(t, 1000, r.Translate(8.0))
-	testutil.AssertEqual(t, 572, r.Translate(5.0))
+	assert.Equal(0, r.Translate(1.0))
+	assert.Equal(1000, r.Translate(8.0))
+	assert.Equal(572, r.Translate(5.0))
 }

continuous_series.go

@@ -2,13 +2,6 @@ package chart
 
 import "fmt"
 
-// Interface Assertions.
-var (
-	_ Series              = (*ContinuousSeries)(nil)
-	_ FirstValuesProvider = (*ContinuousSeries)(nil)
-	_ LastValuesProvider  = (*ContinuousSeries)(nil)
-)
-
 // ContinuousSeries represents a line on a chart.
 type ContinuousSeries struct {
 	Name  string
@@ -38,18 +31,13 @@ func (cs ContinuousSeries) Len() int {
 	return len(cs.XValues)
 }
 
-// GetValues gets the x,y values at a given index.
-func (cs ContinuousSeries) GetValues(index int) (float64, float64) {
+// GetValue gets a value at a given index.
+func (cs ContinuousSeries) GetValue(index int) (float64, float64) {
 	return cs.XValues[index], cs.YValues[index]
 }
 
-// GetFirstValues gets the first x,y values.
-func (cs ContinuousSeries) GetFirstValues() (float64, float64) {
-	return cs.XValues[0], cs.YValues[0]
-}
-
-// GetLastValues gets the last x,y values.
-func (cs ContinuousSeries) GetLastValues() (float64, float64) {
+// GetLastValue gets the last value.
+func (cs ContinuousSeries) GetLastValue() (float64, float64) {
 	return cs.XValues[len(cs.XValues)-1], cs.YValues[len(cs.YValues)-1]
 }
 
@@ -82,15 +70,11 @@ func (cs ContinuousSeries) Render(r Renderer, canvasBox Box, xrange, yrange Rang
 // Validate validates the series.
 func (cs ContinuousSeries) Validate() error {
 	if len(cs.XValues) == 0 {
-		return fmt.Errorf("continuous series; must have xvalues set")
+		return fmt.Errorf("continuous series must have xvalues set")
 	}
 
 	if len(cs.YValues) == 0 {
-		return fmt.Errorf("continuous series; must have yvalues set")
-	}
-
-	if len(cs.XValues) != len(cs.YValues) {
-		return fmt.Errorf("continuous series; must have same length xvalues as yvalues")
+		return fmt.Errorf("continuous series must have yvalues set")
 	}
 	return nil
 }

continuous_series_test.go

@@ -4,35 +4,35 @@ import (
 	"fmt"
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	assert "github.com/blendlabs/go-assert"
 )
 
 func TestContinuousSeries(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	cs := ContinuousSeries{
 		Name:    "Test Series",
-		XValues: LinearRange(1.0, 10.0),
-		YValues: LinearRange(1.0, 10.0),
+		XValues: Sequence.Float64(1.0, 10.0),
+		YValues: Sequence.Float64(1.0, 10.0),
 	}
 
-	testutil.AssertEqual(t, "Test Series", cs.GetName())
-	testutil.AssertEqual(t, 10, cs.Len())
-	x0, y0 := cs.GetValues(0)
-	testutil.AssertEqual(t, 1.0, x0)
-	testutil.AssertEqual(t, 1.0, y0)
+	assert.Equal("Test Series", cs.GetName())
+	assert.Equal(10, cs.Len())
+	x0, y0 := cs.GetValue(0)
+	assert.Equal(1.0, x0)
+	assert.Equal(1.0, y0)
 
-	xn, yn := cs.GetValues(9)
-	testutil.AssertEqual(t, 10.0, xn)
-	testutil.AssertEqual(t, 10.0, yn)
+	xn, yn := cs.GetValue(9)
+	assert.Equal(10.0, xn)
+	assert.Equal(10.0, yn)
 
-	xn, yn = cs.GetLastValues()
-	testutil.AssertEqual(t, 10.0, xn)
-	testutil.AssertEqual(t, 10.0, yn)
+	xn, yn = cs.GetLastValue()
+	assert.Equal(10.0, xn)
+	assert.Equal(10.0, yn)
 }
 
 func TestContinuousSeriesValueFormatter(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	cs := ContinuousSeries{
 		XValueFormatter: func(v interface{}) string {
@@ -44,29 +44,29 @@ func TestContinuousSeriesValueFormatter(t *testing.T) {
 	}
 
 	xf, yf := cs.GetValueFormatters()
-	testutil.AssertEqual(t, "0.100000 foo", xf(0.1))
-	testutil.AssertEqual(t, "0.100000 bar", yf(0.1))
+	assert.Equal("0.100000 foo", xf(0.1))
+	assert.Equal("0.100000 bar", yf(0.1))
 }
 
 func TestContinuousSeriesValidate(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	cs := ContinuousSeries{
 		Name:    "Test Series",
-		XValues: LinearRange(1.0, 10.0),
-		YValues: LinearRange(1.0, 10.0),
+		XValues: Sequence.Float64(1.0, 10.0),
+		YValues: Sequence.Float64(1.0, 10.0),
 	}
-	testutil.AssertNil(t, cs.Validate())
+	assert.Nil(cs.Validate())
 
 	cs = ContinuousSeries{
 		Name:    "Test Series",
-		XValues: LinearRange(1.0, 10.0),
+		XValues: Sequence.Float64(1.0, 10.0),
 	}
-	testutil.AssertNotNil(t, cs.Validate())
+	assert.NotNil(cs.Validate())
 
 	cs = ContinuousSeries{
 		Name:    "Test Series",
-		YValues: LinearRange(1.0, 10.0),
+		YValues: Sequence.Float64(1.0, 10.0),
 	}
-	testutil.AssertNotNil(t, cs.Validate())
+	assert.NotNil(cs.Validate())
 }

date.go

@@ -0,0 +1,426 @@
+package chart
+
+import (
+	"sync"
+	"time"
+)
+
+const (
+	// AllDaysMask is a bitmask of all the days of the week.
+	AllDaysMask = 1<<uint(time.Sunday) | 1<<uint(time.Monday) | 1<<uint(time.Tuesday) | 1<<uint(time.Wednesday) | 1<<uint(time.Thursday) | 1<<uint(time.Friday) | 1<<uint(time.Saturday)
+	// WeekDaysMask is a bitmask of all the weekdays of the week.
+	WeekDaysMask = 1<<uint(time.Monday) | 1<<uint(time.Tuesday) | 1<<uint(time.Wednesday) | 1<<uint(time.Thursday) | 1<<uint(time.Friday)
+	//WeekendDaysMask is a bitmask of the weekend days of the week.
+	WeekendDaysMask = 1<<uint(time.Sunday) | 1<<uint(time.Saturday)
+)
+
+var (
+	// DaysOfWeek are all the time.Weekday in an array for utility purposes.
+	DaysOfWeek = []time.Weekday{
+		time.Sunday,
+		time.Monday,
+		time.Tuesday,
+		time.Wednesday,
+		time.Thursday,
+		time.Friday,
+		time.Saturday,
+	}
+
+	// WeekDays are the business time.Weekday in an array.
+	WeekDays = []time.Weekday{
+		time.Monday,
+		time.Tuesday,
+		time.Wednesday,
+		time.Thursday,
+		time.Friday,
+	}
+
+	// WeekendDays are the weekend time.Weekday in an array.
+	WeekendDays = []time.Weekday{
+		time.Sunday,
+		time.Saturday,
+	}
+
+	//Epoch is unix epoc saved for utility purposes.
+	Epoch = time.Unix(0, 0)
+)
+
+var (
+	_easternLock sync.Mutex
+	_eastern     *time.Location
+)
+
+// NYSEOpen is when the NYSE opens.
+func NYSEOpen() time.Time { return Date.Time(9, 30, 0, 0, Date.Eastern()) }
+
+// NYSEClose is when the NYSE closes.
+func NYSEClose() time.Time { return Date.Time(16, 0, 0, 0, Date.Eastern()) }
+
+// NASDAQOpen is when NASDAQ opens.
+func NASDAQOpen() time.Time { return Date.Time(9, 30, 0, 0, Date.Eastern()) }
+
+// NASDAQClose is when NASDAQ closes.
+func NASDAQClose() time.Time { return Date.Time(16, 0, 0, 0, Date.Eastern()) }
+
+// NYSEArcaOpen is when NYSEARCA opens.
+func NYSEArcaOpen() time.Time { return Date.Time(4, 0, 0, 0, Date.Eastern()) }
+
+// NYSEArcaClose is when NYSEARCA closes.
+func NYSEArcaClose() time.Time { return Date.Time(20, 0, 0, 0, Date.Eastern()) }
+
+// HolidayProvider is a function that returns if a given time falls on a holiday.
+type HolidayProvider func(time.Time) bool
+
+// defaultHolidayProvider implements `HolidayProvider` and just returns false.
+func defaultHolidayProvider(_ time.Time) bool { return false }
+
+var (
+	// Date contains utility functions that operate on dates.
+	Date = &date{}
+)
+
+type date struct{}
+
+// IsNYSEHoliday returns if a date was/is on a nyse holiday day.
+func (d date) IsNYSEHoliday(t time.Time) bool {
+	te := t.In(d.Eastern())
+	if te.Year() == 2013 {
+		if te.Month() == 1 {
+			return te.Day() == 1 || te.Day() == 21
+		} else if te.Month() == 2 {
+			return te.Day() == 18
+		} else if te.Month() == 3 {
+			return te.Day() == 29
+		} else if te.Month() == 5 {
+			return te.Day() == 27
+		} else if te.Month() == 7 {
+			return te.Day() == 4
+		} else if te.Month() == 9 {
+			return te.Day() == 2
+		} else if te.Month() == 11 {
+			return te.Day() == 28
+		} else if te.Month() == 12 {
+			return te.Day() == 25
+		}
+	} else if te.Year() == 2014 {
+		if te.Month() == 1 {
+			return te.Day() == 1 || te.Day() == 20
+		} else if te.Month() == 2 {
+			return te.Day() == 17
+		} else if te.Month() == 4 {
+			return te.Day() == 18
+		} else if te.Month() == 5 {
+			return te.Day() == 26
+		} else if te.Month() == 7 {
+			return te.Day() == 4
+		} else if te.Month() == 9 {
+			return te.Day() == 1
+		} else if te.Month() == 11 {
+			return te.Day() == 27
+		} else if te.Month() == 12 {
+			return te.Day() == 25
+		}
+	} else if te.Year() == 2015 {
+		if te.Month() == 1 {
+			return te.Day() == 1 || te.Day() == 19
+		} else if te.Month() == 2 {
+			return te.Day() == 16
+		} else if te.Month() == 4 {
+			return te.Day() == 3
+		} else if te.Month() == 5 {
+			return te.Day() == 25
+		} else if te.Month() == 7 {
+			return te.Day() == 3
+		} else if te.Month() == 9 {
+			return te.Day() == 7
+		} else if te.Month() == 11 {
+			return te.Day() == 26
+		} else if te.Month() == 12 {
+			return te.Day() == 25
+		}
+	} else if te.Year() == 2016 {
+		if te.Month() == 1 {
+			return te.Day() == 1 || te.Day() == 18
+		} else if te.Month() == 2 {
+			return te.Day() == 15
+		} else if te.Month() == 3 {
+			return te.Day() == 25
+		} else if te.Month() == 5 {
+			return te.Day() == 30
+		} else if te.Month() == 7 {
+			return te.Day() == 4
+		} else if te.Month() == 9 {
+			return te.Day() == 5
+		} else if te.Month() == 11 {
+			return te.Day() == 24 || te.Day() == 25
+		} else if te.Month() == 12 {
+			return te.Day() == 26
+		}
+	} else if te.Year() == 2017 {
+		if te.Month() == 1 {
+			return te.Day() == 1 || te.Day() == 16
+		} else if te.Month() == 2 {
+			return te.Day() == 20
+		} else if te.Month() == 4 {
+			return te.Day() == 15
+		} else if te.Month() == 5 {
+			return te.Day() == 29
+		} else if te.Month() == 7 {
+			return te.Day() == 4
+		} else if te.Month() == 9 {
+			return te.Day() == 4
+		} else if te.Month() == 11 {
+			return te.Day() == 23
+		} else if te.Month() == 12 {
+			return te.Day() == 25
+		}
+	} else if te.Year() == 2018 {
+		if te.Month() == 1 {
+			return te.Day() == 1 || te.Day() == 15
+		} else if te.Month() == 2 {
+			return te.Day() == 19
+		} else if te.Month() == 3 {
+			return te.Day() == 30
+		} else if te.Month() == 5 {
+			return te.Day() == 28
+		} else if te.Month() == 7 {
+			return te.Day() == 4
+		} else if te.Month() == 9 {
+			return te.Day() == 3
+		} else if te.Month() == 11 {
+			return te.Day() == 22
+		} else if te.Month() == 12 {
+			return te.Day() == 25
+		}
+	}
+	return false
+}
+
+// IsNYSEArcaHoliday returns that returns if a given time falls on a holiday.
+func (d date) IsNYSEArcaHoliday(t time.Time) bool {
+	return d.IsNYSEHoliday(t)
+}
+
+// IsNASDAQHoliday returns if a date was a NASDAQ holiday day.
+func (d date) IsNASDAQHoliday(t time.Time) bool {
+	return d.IsNYSEHoliday(t)
+}
+
+// Time returns a new time.Time for the given clock components.
+func (d date) Time(hour, min, sec, nsec int, loc *time.Location) time.Time {
+	return time.Date(0, 0, 0, hour, min, sec, nsec, loc)
+}
+
+func (d date) Date(year, month, day int, loc *time.Location) time.Time {
+	return time.Date(year, time.Month(month), day, 12, 0, 0, 0, loc)
+}
+
+// On returns the clock components of clock (hour,minute,second) on the date components of d.
+func (d date) On(clock, cd time.Time) time.Time {
+	tzAdjusted := cd.In(clock.Location())
+	return time.Date(tzAdjusted.Year(), tzAdjusted.Month(), tzAdjusted.Day(), clock.Hour(), clock.Minute(), clock.Second(), clock.Nanosecond(), clock.Location())
+}
+
+// NoonOn is a shortcut for On(Time(12,0,0), cd) a.k.a. noon on a given date.
+func (d date) NoonOn(cd time.Time) time.Time {
+	return time.Date(cd.Year(), cd.Month(), cd.Day(), 12, 0, 0, 0, cd.Location())
+}
+
+// Optional returns a pointer reference to a given time.
+func (d date) Optional(t time.Time) *time.Time {
+	return &t
+}
+
+// IsWeekDay returns if the day is a monday->friday.
+func (d date) IsWeekDay(day time.Weekday) bool {
+	return !d.IsWeekendDay(day)
+}
+
+// IsWeekendDay returns if the day is a monday->friday.
+func (d date) IsWeekendDay(day time.Weekday) bool {
+	return day == time.Saturday || day == time.Sunday
+}
+
+// Before returns if a timestamp is strictly before another date (ignoring hours, minutes etc.)
+func (d date) Before(before, reference time.Time) bool {
+	tzAdjustedBefore := before.In(reference.Location())
+	if tzAdjustedBefore.Year() < reference.Year() {
+		return true
+	}
+	if tzAdjustedBefore.Month() < reference.Month() {
+		return true
+	}
+	return tzAdjustedBefore.Year() == reference.Year() && tzAdjustedBefore.Month() == reference.Month() && tzAdjustedBefore.Day() < reference.Day()
+}
+
+// NextMarketOpen returns the next market open after a given time.
+func (d date) NextMarketOpen(after, openTime time.Time, isHoliday HolidayProvider) time.Time {
+	afterLocalized := after.In(openTime.Location())
+	todaysOpen := d.On(openTime, afterLocalized)
+
+	if isHoliday == nil {
+		isHoliday = defaultHolidayProvider
+	}
+
+	todayIsValidTradingDay := d.IsWeekDay(todaysOpen.Weekday()) && !isHoliday(todaysOpen)
+
+	if (afterLocalized.Equal(todaysOpen) || afterLocalized.Before(todaysOpen)) && todayIsValidTradingDay {
+		return todaysOpen
+	}
+
+	for cursorDay := 1; cursorDay < 7; cursorDay++ {
+		newDay := todaysOpen.AddDate(0, 0, cursorDay)
+		isValidTradingDay := d.IsWeekDay(newDay.Weekday()) && !isHoliday(newDay)
+		if isValidTradingDay {
+			return d.On(openTime, newDay)
+		}
+	}
+	panic("Have exhausted day window looking for next market open.")
+}
+
+// NextMarketClose returns the next market close after a given time.
+func (d date) NextMarketClose(after, closeTime time.Time, isHoliday HolidayProvider) time.Time {
+	afterLocalized := after.In(closeTime.Location())
+
+	if isHoliday == nil {
+		isHoliday = defaultHolidayProvider
+	}
+
+	todaysClose := d.On(closeTime, afterLocalized)
+	if afterLocalized.Before(todaysClose) && d.IsWeekDay(todaysClose.Weekday()) && !isHoliday(todaysClose) {
+		return todaysClose
+	}
+
+	if afterLocalized.Equal(todaysClose) { //rare but it might happen.
+		return todaysClose
+	}
+
+	for cursorDay := 1; cursorDay < 6; cursorDay++ {
+		newDay := todaysClose.AddDate(0, 0, cursorDay)
+		if d.IsWeekDay(newDay.Weekday()) && !isHoliday(newDay) {
+			return d.On(closeTime, newDay)
+		}
+	}
+	panic("Have exhausted day window looking for next market close.")
+}
+
+// CalculateMarketSecondsBetween calculates the number of seconds the market was open between two dates.
+func (d date) CalculateMarketSecondsBetween(start, end, marketOpen, marketClose time.Time, isHoliday HolidayProvider) (seconds int64) {
+	startEastern := start.In(d.Eastern())
+	endEastern := end.In(d.Eastern())
+
+	startMarketOpen := d.On(marketOpen, startEastern)
+	startMarketClose := d.On(marketClose, startEastern)
+
+	if !d.IsWeekendDay(startMarketOpen.Weekday()) && !isHoliday(startMarketOpen) {
+		if (startEastern.Equal(startMarketOpen) || startEastern.After(startMarketOpen)) && startEastern.Before(startMarketClose) {
+			if endEastern.Before(startMarketClose) {
+				seconds += int64(endEastern.Sub(startEastern) / time.Second)
+			} else {
+				seconds += int64(startMarketClose.Sub(startEastern) / time.Second)
+			}
+		}
+	}
+
+	cursor := d.NextMarketOpen(startMarketClose, marketOpen, isHoliday)
+	for d.Before(cursor, endEastern) {
+		if d.IsWeekDay(cursor.Weekday()) && !isHoliday(cursor) {
+			close := d.NextMarketClose(cursor, marketClose, isHoliday)
+			seconds += int64(close.Sub(cursor) / time.Second)
+		}
+		cursor = cursor.AddDate(0, 0, 1)
+	}
+
+	finalMarketOpen := d.NextMarketOpen(cursor, marketOpen, isHoliday)
+	finalMarketClose := d.NextMarketClose(cursor, marketClose, isHoliday)
+	if endEastern.After(finalMarketOpen) {
+		if endEastern.Before(finalMarketClose) {
+			seconds += int64(endEastern.Sub(finalMarketOpen) / time.Second)
+		} else {
+			seconds += int64(finalMarketClose.Sub(finalMarketOpen) / time.Second)
+		}
+	}
+
+	return
+}
+
+const (
+	_secondsPerHour = 60 * 60
+	_secondsPerDay  = 60 * 60 * 24
+)
+
+func (d date) DiffDays(t1, t2 time.Time) (days int) {
+	t1n := t1.Unix()
+	t2n := t2.Unix()
+	diff := t2n - t1n //yields seconds
+	return int(diff / (_secondsPerDay))
+}
+
+func (d date) DiffHours(t1, t2 time.Time) (hours int) {
+	t1n := t1.Unix()
+	t2n := t2.Unix()
+	diff := t2n - t1n //yields seconds
+	return int(diff / (_secondsPerHour))
+}
+
+// NextDay returns the timestamp advanced a day.
+func (d date) NextDay(ts time.Time) time.Time {
+	return ts.AddDate(0, 0, 1)
+}
+
+// NextHour returns the next timestamp on the hour.
+func (d date) NextHour(ts time.Time) time.Time {
+	//advance a full hour ...
+	advanced := ts.Add(time.Hour)
+	minutes := time.Duration(advanced.Minute()) * time.Minute
+	final := advanced.Add(-minutes)
+	return time.Date(final.Year(), final.Month(), final.Day(), final.Hour(), 0, 0, 0, final.Location())
+}
+
+// NextDayOfWeek returns the next instance of a given weekday after a given timestamp.
+func (d date) NextDayOfWeek(after time.Time, dayOfWeek time.Weekday) time.Time {
+	afterWeekday := after.Weekday()
+	if afterWeekday == dayOfWeek {
+		return after.AddDate(0, 0, 7)
+	}
+
+	// 1 vs 5 ~ add 4 days
+	if afterWeekday < dayOfWeek {
+		dayDelta := int(dayOfWeek - afterWeekday)
+		return after.AddDate(0, 0, dayDelta)
+	}
+
+	// 5 vs 1, add 7-(5-1) ~ 3 days
+	dayDelta := 7 - int(afterWeekday-dayOfWeek)
+	return after.AddDate(0, 0, dayDelta)
+}
+
+// Start returns the earliest (min) time in a list of times.
+func (d date) Start(times []time.Time) time.Time {
+	if len(times) == 0 {
+		return time.Time{}
+	}
+
+	start := times[0]
+	for _, t := range times[1:] {
+		if t.Before(start) {
+			start = t
+		}
+	}
+	return start
+}
+
+// Start returns the earliest (min) time in a list of times.
+func (d date) End(times []time.Time) time.Time {
+	if len(times) == 0 {
+		return time.Time{}
+	}
+
+	end := times[0]
+	for _, t := range times[1:] {
+		if t.After(end) {
+			end = t
+		}
+	}
+	return end
+}

date_posix.go

@@ -0,0 +1,17 @@
+// +build !windows
+
+package chart
+
+import "time"
+
+// Eastern returns the eastern timezone.
+func (d date) Eastern() *time.Location {
+	if _eastern == nil {
+		_easternLock.Lock()
+		defer _easternLock.Unlock()
+		if _eastern == nil {
+			_eastern, _ = time.LoadLocation("America/New_York")
+		}
+	}
+	return _eastern
+}

date_test.go

@@ -0,0 +1,288 @@
+package chart
+
+import (
+	"testing"
+	"time"
+
+	assert "github.com/blendlabs/go-assert"
+)
+
+func parse(v string) time.Time {
+	ts, _ := time.Parse("2006-01-02", v)
+	return ts
+}
+
+func TestDateTime(t *testing.T) {
+	assert := assert.New(t)
+
+	ts := Date.Time(5, 6, 7, 8, time.UTC)
+	assert.Equal(05, ts.Hour())
+	assert.Equal(06, ts.Minute())
+	assert.Equal(07, ts.Second())
+	assert.Equal(8, ts.Nanosecond())
+	assert.Equal(time.UTC, ts.Location())
+}
+
+func TestDateDate(t *testing.T) {
+	assert := assert.New(t)
+
+	ts := Date.Date(2015, 5, 6, time.UTC)
+	assert.Equal(2015, ts.Year())
+	assert.Equal(5, ts.Month())
+	assert.Equal(6, ts.Day())
+	assert.Equal(time.UTC, ts.Location())
+}
+
+func TestDateOn(t *testing.T) {
+	assert := assert.New(t)
+
+	ts := Date.On(Date.Time(5, 4, 3, 2, time.UTC), Date.Date(2016, 6, 7, Date.Eastern()))
+	assert.Equal(2016, ts.Year())
+	assert.Equal(6, ts.Month())
+	assert.Equal(7, ts.Day())
+	assert.Equal(5, ts.Hour())
+	assert.Equal(4, ts.Minute())
+	assert.Equal(3, ts.Second())
+	assert.Equal(2, ts.Nanosecond())
+	assert.Equal(time.UTC, ts.Location())
+}
+
+func TestDateNoonOn(t *testing.T) {
+	assert := assert.New(t)
+	noon := Date.NoonOn(time.Date(2016, 04, 03, 02, 01, 0, 0, time.UTC))
+
+	assert.Equal(2016, noon.Year())
+	assert.Equal(4, noon.Month())
+	assert.Equal(3, noon.Day())
+	assert.Equal(12, noon.Hour())
+	assert.Equal(0, noon.Minute())
+	assert.Equal(time.UTC, noon.Location())
+}
+
+func TestDateBefore(t *testing.T) {
+	assert := assert.New(t)
+
+	assert.True(Date.Before(parse("2015-07-02"), parse("2016-07-01")))
+	assert.True(Date.Before(parse("2016-06-01"), parse("2016-07-01")))
+	assert.True(Date.Before(parse("2016-07-01"), parse("2016-07-02")))
+
+	assert.False(Date.Before(parse("2016-07-01"), parse("2016-07-01")))
+	assert.False(Date.Before(parse("2016-07-03"), parse("2016-07-01")))
+	assert.False(Date.Before(parse("2016-08-03"), parse("2016-07-01")))
+	assert.False(Date.Before(parse("2017-08-03"), parse("2016-07-01")))
+}
+
+func TestDateBeforeHandlesTimezones(t *testing.T) {
+	assert := assert.New(t)
+
+	tuesdayUTC := time.Date(2016, 8, 02, 22, 00, 0, 0, time.UTC)
+	mondayUTC := time.Date(2016, 8, 01, 1, 00, 0, 0, time.UTC)
+	sundayEST := time.Date(2016, 7, 31, 22, 00, 0, 0, Date.Eastern())
+
+	assert.True(Date.Before(sundayEST, tuesdayUTC))
+	assert.False(Date.Before(sundayEST, mondayUTC))
+}
+
+func TestNextMarketOpen(t *testing.T) {
+	assert := assert.New(t)
+
+	beforeOpen := time.Date(2016, 07, 18, 9, 0, 0, 0, Date.Eastern())
+	todayOpen := time.Date(2016, 07, 18, 9, 30, 0, 0, Date.Eastern())
+
+	afterOpen := time.Date(2016, 07, 18, 9, 31, 0, 0, Date.Eastern())
+	tomorrowOpen := time.Date(2016, 07, 19, 9, 30, 0, 0, Date.Eastern())
+
+	afterFriday := time.Date(2016, 07, 22, 9, 31, 0, 0, Date.Eastern())
+	mondayOpen := time.Date(2016, 07, 25, 9, 30, 0, 0, Date.Eastern())
+
+	weekend := time.Date(2016, 07, 23, 9, 31, 0, 0, Date.Eastern())
+
+	assert.True(todayOpen.Equal(Date.NextMarketOpen(beforeOpen, NYSEOpen(), Date.IsNYSEHoliday)))
+	assert.True(tomorrowOpen.Equal(Date.NextMarketOpen(afterOpen, NYSEOpen(), Date.IsNYSEHoliday)))
+	assert.True(mondayOpen.Equal(Date.NextMarketOpen(afterFriday, NYSEOpen(), Date.IsNYSEHoliday)))
+	assert.True(mondayOpen.Equal(Date.NextMarketOpen(weekend, NYSEOpen(), Date.IsNYSEHoliday)))
+
+	assert.Equal(Date.Eastern(), todayOpen.Location())
+	assert.Equal(Date.Eastern(), tomorrowOpen.Location())
+	assert.Equal(Date.Eastern(), mondayOpen.Location())
+
+	testRegression := time.Date(2016, 07, 18, 16, 0, 0, 0, Date.Eastern())
+	shouldbe := time.Date(2016, 07, 19, 9, 30, 0, 0, Date.Eastern())
+
+	assert.True(shouldbe.Equal(Date.NextMarketOpen(testRegression, NYSEOpen(), Date.IsNYSEHoliday)))
+}
+
+func TestNextMarketClose(t *testing.T) {
+	assert := assert.New(t)
+
+	beforeClose := time.Date(2016, 07, 18, 15, 0, 0, 0, Date.Eastern())
+	todayClose := time.Date(2016, 07, 18, 16, 00, 0, 0, Date.Eastern())
+
+	afterClose := time.Date(2016, 07, 18, 16, 1, 0, 0, Date.Eastern())
+	tomorrowClose := time.Date(2016, 07, 19, 16, 00, 0, 0, Date.Eastern())
+
+	afterFriday := time.Date(2016, 07, 22, 16, 1, 0, 0, Date.Eastern())
+	mondayClose := time.Date(2016, 07, 25, 16, 0, 0, 0, Date.Eastern())
+
+	weekend := time.Date(2016, 07, 23, 9, 31, 0, 0, Date.Eastern())
+
+	assert.True(todayClose.Equal(Date.NextMarketClose(beforeClose, NYSEClose(), Date.IsNYSEHoliday)))
+	assert.True(tomorrowClose.Equal(Date.NextMarketClose(afterClose, NYSEClose(), Date.IsNYSEHoliday)))
+	assert.True(mondayClose.Equal(Date.NextMarketClose(afterFriday, NYSEClose(), Date.IsNYSEHoliday)))
+	assert.True(mondayClose.Equal(Date.NextMarketClose(weekend, NYSEClose(), Date.IsNYSEHoliday)))
+
+	assert.Equal(Date.Eastern(), todayClose.Location())
+	assert.Equal(Date.Eastern(), tomorrowClose.Location())
+	assert.Equal(Date.Eastern(), mondayClose.Location())
+}
+
+func TestCalculateMarketSecondsBetween(t *testing.T) {
+	assert := assert.New(t)
+
+	start := time.Date(2016, 07, 18, 9, 30, 0, 0, Date.Eastern())
+	end := time.Date(2016, 07, 22, 16, 00, 0, 0, Date.Eastern())
+
+	shouldbe := 5 * 6.5 * 60 * 60
+
+	assert.Equal(shouldbe, Date.CalculateMarketSecondsBetween(start, end, NYSEOpen(), NYSEClose(), Date.IsNYSEHoliday))
+}
+
+func TestCalculateMarketSecondsBetween1D(t *testing.T) {
+	assert := assert.New(t)
+
+	start := time.Date(2016, 07, 22, 9, 45, 0, 0, Date.Eastern())
+	end := time.Date(2016, 07, 22, 15, 45, 0, 0, Date.Eastern())
+
+	shouldbe := 6 * 60 * 60
+
+	assert.Equal(shouldbe, Date.CalculateMarketSecondsBetween(start, end, NYSEOpen(), NYSEClose(), Date.IsNYSEHoliday))
+}
+
+func TestCalculateMarketSecondsBetweenLTM(t *testing.T) {
+	assert := assert.New(t)
+
+	start := time.Date(2015, 07, 01, 9, 30, 0, 0, Date.Eastern())
+	end := time.Date(2016, 07, 01, 9, 30, 0, 0, Date.Eastern())
+
+	shouldbe := 253 * 6.5 * 60 * 60 //253 full market days since this date last year.
+	assert.Equal(shouldbe, Date.CalculateMarketSecondsBetween(start, end, NYSEOpen(), NYSEClose(), Date.IsNYSEHoliday))
+}
+
+func TestDateNextHour(t *testing.T) {
+	assert := assert.New(t)
+
+	start := time.Date(2015, 07, 01, 9, 30, 0, 0, Date.Eastern())
+	next := Date.NextHour(start)
+	assert.Equal(2015, next.Year())
+	assert.Equal(07, next.Month())
+	assert.Equal(01, next.Day())
+	assert.Equal(10, next.Hour())
+	assert.Equal(00, next.Minute())
+
+	next = Date.NextHour(next)
+	assert.Equal(11, next.Hour())
+
+	next = Date.NextHour(next)
+	assert.Equal(12, next.Hour())
+
+}
+
+func TestDateNextDayOfWeek(t *testing.T) {
+	assert := assert.New(t)
+
+	weds := Date.Date(2016, 8, 10, time.UTC)
+	fri := Date.Date(2016, 8, 12, time.UTC)
+	sun := Date.Date(2016, 8, 14, time.UTC)
+	mon := Date.Date(2016, 8, 15, time.UTC)
+	weds2 := Date.Date(2016, 8, 17, time.UTC)
+
+	nextFri := Date.NextDayOfWeek(weds, time.Friday)
+	nextSunday := Date.NextDayOfWeek(weds, time.Sunday)
+	nextMonday := Date.NextDayOfWeek(weds, time.Monday)
+	nextWeds := Date.NextDayOfWeek(weds, time.Wednesday)
+
+	assert.Equal(fri.Year(), nextFri.Year())
+	assert.Equal(fri.Month(), nextFri.Month())
+	assert.Equal(fri.Day(), nextFri.Day())
+
+	assert.Equal(sun.Year(), nextSunday.Year())
+	assert.Equal(sun.Month(), nextSunday.Month())
+	assert.Equal(sun.Day(), nextSunday.Day())
+
+	assert.Equal(mon.Year(), nextMonday.Year())
+	assert.Equal(mon.Month(), nextMonday.Month())
+	assert.Equal(mon.Day(), nextMonday.Day())
+
+	assert.Equal(weds2.Year(), nextWeds.Year())
+	assert.Equal(weds2.Month(), nextWeds.Month())
+	assert.Equal(weds2.Day(), nextWeds.Day())
+
+	assert.Equal(time.UTC, nextFri.Location())
+	assert.Equal(time.UTC, nextSunday.Location())
+	assert.Equal(time.UTC, nextMonday.Location())
+}
+
+func TestDateIsNYSEHoliday(t *testing.T) {
+	assert := assert.New(t)
+
+	cursor := time.Date(2013, 01, 01, 0, 0, 0, 0, time.UTC)
+	end := time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)
+	var holidays int
+	for Date.Before(cursor, end) {
+		if Date.IsNYSEHoliday(cursor) {
+			holidays++
+		}
+		cursor = cursor.AddDate(0, 0, 1)
+	}
+	assert.Equal(holidays, 55)
+}
+
+func TestTimeStart(t *testing.T) {
+	assert := assert.New(t)
+
+	times := []time.Time{
+		time.Now().AddDate(0, 0, -4),
+		time.Now().AddDate(0, 0, -2),
+		time.Now().AddDate(0, 0, -1),
+		time.Now().AddDate(0, 0, -3),
+		time.Now().AddDate(0, 0, -5),
+	}
+
+	assert.InTimeDelta(Date.Start(times), times[4], time.Millisecond)
+}
+
+func TestTimeEnd(t *testing.T) {
+	assert := assert.New(t)
+
+	times := []time.Time{
+		time.Now().AddDate(0, 0, -4),
+		time.Now().AddDate(0, 0, -2),
+		time.Now().AddDate(0, 0, -1),
+		time.Now().AddDate(0, 0, -3),
+		time.Now().AddDate(0, 0, -5),
+	}
+
+	assert.InTimeDelta(Date.End(times), times[2], time.Millisecond)
+}
+
+func TestDateDiffDays(t *testing.T) {
+	assert := assert.New(t)
+
+	t1 := time.Date(2017, 02, 27, 12, 0, 0, 0, time.UTC)
+	t2 := time.Date(2017, 01, 10, 3, 0, 0, 0, time.UTC)
+	t3 := time.Date(2017, 02, 24, 16, 0, 0, 0, time.UTC)
+
+	assert.Equal(48, Date.DiffDays(t2, t1))
+	assert.Equal(2, Date.DiffDays(t3, t1)) // technically we should round down.
+}
+
+func TestDateDiffHours(t *testing.T) {
+	assert := assert.New(t)
+
+	t1 := time.Date(2017, 02, 27, 12, 0, 0, 0, time.UTC)
+	t2 := time.Date(2017, 02, 24, 16, 0, 0, 0, time.UTC)
+	t3 := time.Date(2017, 02, 28, 12, 0, 0, 0, time.UTC)
+
+	assert.Equal(68, Date.DiffHours(t2, t1))
+	assert.Equal(24, Date.DiffHours(t1, t3))
+}

date_windows.go

@@ -0,0 +1,17 @@
+// +build windows
+
+package chart
+
+import "time"
+
+// Eastern returns the eastern timezone.
+func (d date) Eastern() *time.Location {
+	if _eastern == nil {
+		_easternLock.Lock()
+		defer _easternLock.Unlock()
+		if _eastern == nil {
+			_eastern, _ = time.LoadLocation("EST")
+		}
+	}
+	return _eastern
+}

defaults.go

@@ -1,5 +1,12 @@
 package chart
 
+import (
+	"sync"
+
+	"github.com/golang/freetype/truetype"
+	"github.com/wcharczuk/go-chart/drawing"
+)
+
 const (
 	// DefaultChartHeight is the default chart height.
 	DefaultChartHeight = 400
@@ -75,6 +82,96 @@ const (
 	DefaultBarWidth = 50
 )
 
+var (
+	// ColorWhite is white.
+	ColorWhite = drawing.Color{R: 255, G: 255, B: 255, A: 255}
+	// ColorBlue is the basic theme blue color.
+	ColorBlue = drawing.Color{R: 0, G: 116, B: 217, A: 255}
+	// ColorCyan is the basic theme cyan color.
+	ColorCyan = drawing.Color{R: 0, G: 217, B: 210, A: 255}
+	// ColorGreen is the basic theme green color.
+	ColorGreen = drawing.Color{R: 0, G: 217, B: 101, A: 255}
+	// ColorRed is the basic theme red color.
+	ColorRed = drawing.Color{R: 217, G: 0, B: 116, A: 255}
+	// ColorOrange is the basic theme orange color.
+	ColorOrange = drawing.Color{R: 217, G: 101, B: 0, A: 255}
+	// ColorYellow is the basic theme yellow color.
+	ColorYellow = drawing.Color{R: 217, G: 210, B: 0, A: 255}
+	// ColorBlack is the basic theme black color.
+	ColorBlack = drawing.Color{R: 51, G: 51, B: 51, A: 255}
+	// ColorLightGray is the basic theme light gray color.
+	ColorLightGray = drawing.Color{R: 239, G: 239, B: 239, A: 255}
+
+	// ColorAlternateBlue is a alternate theme color.
+	ColorAlternateBlue = drawing.Color{R: 106, G: 195, B: 203, A: 255}
+	// ColorAlternateGreen is a alternate theme color.
+	ColorAlternateGreen = drawing.Color{R: 42, G: 190, B: 137, A: 255}
+	// ColorAlternateGray is a alternate theme color.
+	ColorAlternateGray = drawing.Color{R: 110, G: 128, B: 139, A: 255}
+	// ColorAlternateYellow is a alternate theme color.
+	ColorAlternateYellow = drawing.Color{R: 240, G: 174, B: 90, A: 255}
+	// ColorAlternateLightGray is a alternate theme color.
+	ColorAlternateLightGray = drawing.Color{R: 187, G: 190, B: 191, A: 255}
+
+	// ColorTransparent is a transparent (alpha zero) color.
+	ColorTransparent = drawing.Color{R: 1, G: 1, B: 1, A: 0}
+)
+
+var (
+	// DefaultBackgroundColor is the default chart background color.
+	// It is equivalent to css color:white.
+	DefaultBackgroundColor = ColorWhite
+	// DefaultBackgroundStrokeColor is the default chart border color.
+	// It is equivalent to color:white.
+	DefaultBackgroundStrokeColor = ColorWhite
+	// DefaultCanvasColor is the default chart canvas color.
+	// It is equivalent to css color:white.
+	DefaultCanvasColor = ColorWhite
+	// DefaultCanvasStrokeColor is the default chart canvas stroke color.
+	// It is equivalent to css color:white.
+	DefaultCanvasStrokeColor = ColorWhite
+	// DefaultTextColor is the default chart text color.
+	// It is equivalent to #333333.
+	DefaultTextColor = ColorBlack
+	// DefaultAxisColor is the default chart axis line color.
+	// It is equivalent to #333333.
+	DefaultAxisColor = ColorBlack
+	// DefaultStrokeColor is the default chart border color.
+	// It is equivalent to #efefef.
+	DefaultStrokeColor = ColorLightGray
+	// DefaultFillColor is the default fill color.
+	// It is equivalent to #0074d9.
+	DefaultFillColor = ColorBlue
+	// DefaultAnnotationFillColor is the default annotation background color.
+	DefaultAnnotationFillColor = ColorWhite
+	// DefaultGridLineColor is the default grid line color.
+	DefaultGridLineColor = ColorLightGray
+)
+
+var (
+	// DefaultColors are a couple default series colors.
+	DefaultColors = []drawing.Color{
+		ColorBlue,
+		ColorGreen,
+		ColorRed,
+		ColorCyan,
+		ColorOrange,
+	}
+
+	// DefaultAlternateColors are a couple alternate colors.
+	DefaultAlternateColors = []drawing.Color{
+		ColorAlternateBlue,
+		ColorAlternateGreen,
+		ColorAlternateGray,
+		ColorAlternateYellow,
+		ColorBlue,
+		ColorGreen,
+		ColorRed,
+		ColorCyan,
+		ColorOrange,
+	}
+)
+
 var (
 	// DashArrayDots is a dash array that represents '....' style stroke dashes.
 	DashArrayDots = []int{1, 1}
@@ -86,18 +183,49 @@ var (
 	DashArrayDashesLarge = []int{10, 10}
 )
 
+// NewColor returns a new color.
+func NewColor(r, g, b, a uint8) drawing.Color {
+	return drawing.Color{R: r, G: g, B: b, A: a}
+}
+
+// GetDefaultColor returns a color from the default list by index.
+// NOTE: the index will wrap around (using a modulo).
+func GetDefaultColor(index int) drawing.Color {
+	finalIndex := index % len(DefaultColors)
+	return DefaultColors[finalIndex]
+}
+
+// GetAlternateColor returns a color from the default list by index.
+// NOTE: the index will wrap around (using a modulo).
+func GetAlternateColor(index int) drawing.Color {
+	finalIndex := index % len(DefaultAlternateColors)
+	return DefaultAlternateColors[finalIndex]
+}
+
 var (
 	// DefaultAnnotationPadding is the padding around an annotation.
 	DefaultAnnotationPadding = Box{Top: 5, Left: 5, Right: 5, Bottom: 5}
-
 	// DefaultBackgroundPadding is the default canvas padding config.
 	DefaultBackgroundPadding = Box{Top: 5, Left: 5, Right: 5, Bottom: 5}
 )
 
-const (
-	// ContentTypePNG is the png mime type.
-	ContentTypePNG = "image/png"
-
-	// ContentTypeSVG is the svg mime type.
-	ContentTypeSVG = "image/svg+xml"
+var (
+	_defaultFontLock sync.Mutex
+	_defaultFont     *truetype.Font
 )
+
+// GetDefaultFont returns the default font (Roboto-Medium).
+func GetDefaultFont() (*truetype.Font, error) {
+	if _defaultFont == nil {
+		_defaultFontLock.Lock()
+		defer _defaultFontLock.Unlock()
+		if _defaultFont == nil {
+			font, err := truetype.Parse(roboto)
+			if err != nil {
+				return nil, err
+			}
+			_defaultFont = font
+		}
+	}
+	return _defaultFont, nil
+}

donut_chart.go

@@ -1,315 +0,0 @@
-package chart
-
-import (
-	"errors"
-	"fmt"
-	"io"
-
-	"github.com/golang/freetype/truetype"
-)
-
-// DonutChart is a chart that draws sections of a circle based on percentages with an hole.
-type DonutChart struct {
-	Title      string
-	TitleStyle Style
-
-	ColorPalette ColorPalette
-
-	Width  int
-	Height int
-	DPI    float64
-
-	Background Style
-	Canvas     Style
-	SliceStyle Style
-
-	Font        *truetype.Font
-	defaultFont *truetype.Font
-
-	Values   []Value
-	Elements []Renderable
-}
-
-// GetDPI returns the dpi for the chart.
-func (pc DonutChart) GetDPI(defaults ...float64) float64 {
-	if pc.DPI == 0 {
-		if len(defaults) > 0 {
-			return defaults[0]
-		}
-		return DefaultDPI
-	}
-	return pc.DPI
-}
-
-// GetFont returns the text font.
-func (pc DonutChart) GetFont() *truetype.Font {
-	if pc.Font == nil {
-		return pc.defaultFont
-	}
-	return pc.Font
-}
-
-// GetWidth returns the chart width or the default value.
-func (pc DonutChart) GetWidth() int {
-	if pc.Width == 0 {
-		return DefaultChartWidth
-	}
-	return pc.Width
-}
-
-// GetHeight returns the chart height or the default value.
-func (pc DonutChart) GetHeight() int {
-	if pc.Height == 0 {
-		return DefaultChartWidth
-	}
-	return pc.Height
-}
-
-// Render renders the chart with the given renderer to the given io.Writer.
-func (pc DonutChart) Render(rp RendererProvider, w io.Writer) error {
-	if len(pc.Values) == 0 {
-		return errors.New("please provide at least one value")
-	}
-
-	r, err := rp(pc.GetWidth(), pc.GetHeight())
-	if err != nil {
-		return err
-	}
-
-	if pc.Font == nil {
-		defaultFont, err := GetDefaultFont()
-		if err != nil {
-			return err
-		}
-		pc.defaultFont = defaultFont
-	}
-	r.SetDPI(pc.GetDPI(DefaultDPI))
-
-	canvasBox := pc.getDefaultCanvasBox()
-	canvasBox = pc.getCircleAdjustedCanvasBox(canvasBox)
-
-	pc.drawBackground(r)
-	pc.drawCanvas(r, canvasBox)
-
-	finalValues, err := pc.finalizeValues(pc.Values)
-	if err != nil {
-		return err
-	}
-	pc.drawSlices(r, canvasBox, finalValues)
-	pc.drawTitle(r)
-	for _, a := range pc.Elements {
-		a(r, canvasBox, pc.styleDefaultsElements())
-	}
-
-	return r.Save(w)
-}
-
-func (pc DonutChart) drawBackground(r Renderer) {
-	Draw.Box(r, Box{
-		Right:  pc.GetWidth(),
-		Bottom: pc.GetHeight(),
-	}, pc.getBackgroundStyle())
-}
-
-func (pc DonutChart) drawCanvas(r Renderer, canvasBox Box) {
-	Draw.Box(r, canvasBox, pc.getCanvasStyle())
-}
-
-func (pc DonutChart) drawTitle(r Renderer) {
-	if len(pc.Title) > 0 && !pc.TitleStyle.Hidden {
-		Draw.TextWithin(r, pc.Title, pc.Box(), pc.styleDefaultsTitle())
-	}
-}
-
-func (pc DonutChart) drawSlices(r Renderer, canvasBox Box, values []Value) {
-	cx, cy := canvasBox.Center()
-	diameter := MinInt(canvasBox.Width(), canvasBox.Height())
-	radius := float64(diameter>>1) / 1.1
-	labelRadius := (radius * 2.83) / 3.0
-
-	// draw the donut slices
-	var rads, delta, delta2, total float64
-	var lx, ly int
-
-	if len(values) == 1 {
-		pc.styleDonutChartValue(0).WriteToRenderer(r)
-		r.MoveTo(cx, cy)
-		r.Circle(radius, cx, cy)
-	} else {
-		for index, v := range values {
-			v.Style.InheritFrom(pc.styleDonutChartValue(index)).WriteToRenderer(r)
-			r.MoveTo(cx, cy)
-			rads = PercentToRadians(total)
-			delta = PercentToRadians(v.Value)
-
-			r.ArcTo(cx, cy, (radius / 1.25), (radius / 1.25), rads, delta)
-
-			r.LineTo(cx, cy)
-			r.Close()
-			r.FillStroke()
-			total = total + v.Value
-		}
-	}
-
-	//making the donut hole
-	v := Value{Value: 100, Label: "center"}
-	styletemp := pc.SliceStyle.InheritFrom(Style{
-		StrokeColor: ColorWhite, StrokeWidth: 4.0, FillColor: ColorWhite, FontColor: ColorWhite, //Font:        pc.GetFont(),//FontSize:    pc.getScaledFontSize(),
-	})
-	v.Style.InheritFrom(styletemp).WriteToRenderer(r)
-	r.MoveTo(cx, cy)
-	r.ArcTo(cx, cy, (radius / 3.5), (radius / 3.5), DegreesToRadians(0), DegreesToRadians(359))
-	r.LineTo(cx, cy)
-	r.Close()
-	r.FillStroke()
-
-	// draw the labels
-	total = 0
-	for index, v := range values {
-		v.Style.InheritFrom(pc.styleDonutChartValue(index)).WriteToRenderer(r)
-		if len(v.Label) > 0 {
-			delta2 = PercentToRadians(total + (v.Value / 2.0))
-			delta2 = RadianAdd(delta2, _pi2)
-			lx, ly = CirclePoint(cx, cy, labelRadius, delta2)
-
-			tb := r.MeasureText(v.Label)
-			lx = lx - (tb.Width() >> 1)
-			ly = ly + (tb.Height() >> 1)
-
-			r.Text(v.Label, lx, ly)
-		}
-		total = total + v.Value
-	}
-}
-
-func (pc DonutChart) finalizeValues(values []Value) ([]Value, error) {
-	finalValues := Values(values).Normalize()
-	if len(finalValues) == 0 {
-		return nil, fmt.Errorf("donut chart must contain at least (1) non-zero value")
-	}
-	return finalValues, nil
-}
-
-func (pc DonutChart) getDefaultCanvasBox() Box {
-	return pc.Box()
-}
-
-func (pc DonutChart) getCircleAdjustedCanvasBox(canvasBox Box) Box {
-	circleDiameter := MinInt(canvasBox.Width(), canvasBox.Height())
-
-	square := Box{
-		Right:  circleDiameter,
-		Bottom: circleDiameter,
-	}
-
-	return canvasBox.Fit(square)
-}
-
-func (pc DonutChart) getBackgroundStyle() Style {
-	return pc.Background.InheritFrom(pc.styleDefaultsBackground())
-}
-
-func (pc DonutChart) getCanvasStyle() Style {
-	return pc.Canvas.InheritFrom(pc.styleDefaultsCanvas())
-}
-
-func (pc DonutChart) styleDefaultsCanvas() Style {
-	return Style{
-		FillColor:   pc.GetColorPalette().CanvasColor(),
-		StrokeColor: pc.GetColorPalette().CanvasStrokeColor(),
-		StrokeWidth: DefaultStrokeWidth,
-	}
-}
-
-func (pc DonutChart) styleDefaultsDonutChartValue() Style {
-	return Style{
-		StrokeColor: pc.GetColorPalette().TextColor(),
-		StrokeWidth: 4.0,
-		FillColor:   pc.GetColorPalette().TextColor(),
-	}
-}
-
-func (pc DonutChart) styleDonutChartValue(index int) Style {
-	return pc.SliceStyle.InheritFrom(Style{
-		StrokeColor: ColorWhite,
-		StrokeWidth: 4.0,
-		FillColor:   pc.GetColorPalette().GetSeriesColor(index),
-		FontSize:    pc.getScaledFontSize(),
-		FontColor:   pc.GetColorPalette().TextColor(),
-		Font:        pc.GetFont(),
-	})
-}
-
-func (pc DonutChart) getScaledFontSize() float64 {
-	effectiveDimension := MinInt(pc.GetWidth(), pc.GetHeight())
-	if effectiveDimension >= 2048 {
-		return 48.0
-	} else if effectiveDimension >= 1024 {
-		return 24.0
-	} else if effectiveDimension > 512 {
-		return 18.0
-	} else if effectiveDimension > 256 {
-		return 12.0
-	}
-	return 10.0
-}
-
-func (pc DonutChart) styleDefaultsBackground() Style {
-	return Style{
-		FillColor:   pc.GetColorPalette().BackgroundColor(),
-		StrokeColor: pc.GetColorPalette().BackgroundStrokeColor(),
-		StrokeWidth: DefaultStrokeWidth,
-	}
-}
-
-func (pc DonutChart) styleDefaultsElements() Style {
-	return Style{
-		Font: pc.GetFont(),
-	}
-}
-
-func (pc DonutChart) styleDefaultsTitle() Style {
-	return pc.TitleStyle.InheritFrom(Style{
-		FontColor:           pc.GetColorPalette().TextColor(),
-		Font:                pc.GetFont(),
-		FontSize:            pc.getTitleFontSize(),
-		TextHorizontalAlign: TextHorizontalAlignCenter,
-		TextVerticalAlign:   TextVerticalAlignTop,
-		TextWrap:            TextWrapWord,
-	})
-}
-
-func (pc DonutChart) getTitleFontSize() float64 {
-	effectiveDimension := MinInt(pc.GetWidth(), pc.GetHeight())
-	if effectiveDimension >= 2048 {
-		return 48
-	} else if effectiveDimension >= 1024 {
-		return 24
-	} else if effectiveDimension >= 512 {
-		return 18
-	} else if effectiveDimension >= 256 {
-		return 12
-	}
-	return 10
-}
-
-// GetColorPalette returns the color palette for the chart.
-func (pc DonutChart) GetColorPalette() ColorPalette {
-	if pc.ColorPalette != nil {
-		return pc.ColorPalette
-	}
-	return AlternateColorPalette
-}
-
-// Box returns the chart bounds as a box.
-func (pc DonutChart) Box() Box {
-	dpr := pc.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
-	dpb := pc.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
-
-	return Box{
-		Top:    pc.Background.Padding.GetTop(DefaultBackgroundPadding.Top),
-		Left:   pc.Background.Padding.GetLeft(DefaultBackgroundPadding.Left),
-		Right:  pc.GetWidth() - dpr,
-		Bottom: pc.GetHeight() - dpb,
-	}
-}

donut_chart_test.go

@@ -1,69 +0,0 @@
-package chart
-
-import (
-	"bytes"
-	"testing"
-
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
-)
-
-func TestDonutChart(t *testing.T) {
-	// replaced new assertions helper
-
-	pie := DonutChart{
-		Canvas: Style{
-			FillColor: ColorLightGray,
-		},
-		Values: []Value{
-			{Value: 10, Label: "Blue"},
-			{Value: 9, Label: "Green"},
-			{Value: 8, Label: "Gray"},
-			{Value: 7, Label: "Orange"},
-			{Value: 6, Label: "HEANG"},
-			{Value: 5, Label: "??"},
-			{Value: 2, Label: "!!"},
-		},
-	}
-
-	b := bytes.NewBuffer([]byte{})
-	pie.Render(PNG, b)
-	testutil.AssertNotZero(t, b.Len())
-}
-
-func TestDonutChartDropsZeroValues(t *testing.T) {
-	// replaced new assertions helper
-
-	pie := DonutChart{
-		Canvas: Style{
-			FillColor: ColorLightGray,
-		},
-		Values: []Value{
-			{Value: 5, Label: "Blue"},
-			{Value: 5, Label: "Green"},
-			{Value: 0, Label: "Gray"},
-		},
-	}
-
-	b := bytes.NewBuffer([]byte{})
-	err := pie.Render(PNG, b)
-	testutil.AssertNil(t, err)
-}
-
-func TestDonutChartAllZeroValues(t *testing.T) {
-	// replaced new assertions helper
-
-	pie := DonutChart{
-		Canvas: Style{
-			FillColor: ColorLightGray,
-		},
-		Values: []Value{
-			{Value: 0, Label: "Blue"},
-			{Value: 0, Label: "Green"},
-			{Value: 0, Label: "Gray"},
-		},
-	}
-
-	b := bytes.NewBuffer([]byte{})
-	err := pie.Render(PNG, b)
-	testutil.AssertNotNil(t, err)
-}

draw.go

@@ -1,8 +1,6 @@
 package chart
 
-import (
-	"math"
-)
+import "math"
 
 var (
 	// Draw contains helpers for drawing common objects.
@@ -12,7 +10,7 @@ var (
 type draw struct{}
 
 // LineSeries draws a line series with a renderer.
-func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, vs ValuesProvider) {
+func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, vs ValueProvider) {
 	if vs.Len() == 0 {
 		return
 	}
@@ -20,7 +18,7 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
 	cb := canvasBox.Bottom
 	cl := canvasBox.Left
 
-	v0x, v0y := vs.GetValues(0)
+	v0x, v0y := vs.GetValue(0)
 	x0 := cl + xrange.Translate(v0x)
 	y0 := cb - yrange.Translate(v0y)
 
@@ -33,13 +31,13 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
 		style.GetFillOptions().WriteDrawingOptionsToRenderer(r)
 		r.MoveTo(x0, y0)
 		for i := 1; i < vs.Len(); i++ {
-			vx, vy = vs.GetValues(i)
+			vx, vy = vs.GetValue(i)
 			x = cl + xrange.Translate(vx)
 			y = cb - yrange.Translate(vy)
 			r.LineTo(x, y)
 		}
-		r.LineTo(x, MinInt(cb, cb-yv0))
-		r.LineTo(x0, MinInt(cb, cb-yv0))
+		r.LineTo(x, Math.MinInt(cb, cb-yv0))
+		r.LineTo(x0, Math.MinInt(cb, cb-yv0))
 		r.LineTo(x0, y0)
 		r.Fill()
 	}
@@ -49,7 +47,7 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
 
 		r.MoveTo(x0, y0)
 		for i := 1; i < vs.Len(); i++ {
-			vx, vy = vs.GetValues(i)
+			vx, vy = vs.GetValue(i)
 			x = cl + xrange.Translate(vx)
 			y = cb - yrange.Translate(vy)
 			r.LineTo(x, y)
@@ -58,34 +56,23 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
 	}
 
 	if style.ShouldDrawDot() {
-		defaultDotWidth := style.GetDotWidth()
+		dotWidth := style.GetDotWidth()
 
 		style.GetDotOptions().WriteDrawingOptionsToRenderer(r)
+
 		for i := 0; i < vs.Len(); i++ {
-			vx, vy = vs.GetValues(i)
+			vx, vy = vs.GetValue(i)
 			x = cl + xrange.Translate(vx)
 			y = cb - yrange.Translate(vy)
 
-			dotWidth := defaultDotWidth
-			if style.DotWidthProvider != nil {
-				dotWidth = style.DotWidthProvider(xrange, yrange, i, vx, vy)
-			}
-
-			if style.DotColorProvider != nil {
-				dotColor := style.DotColorProvider(xrange, yrange, i, vx, vy)
-
-				r.SetFillColor(dotColor)
-				r.SetStrokeColor(dotColor)
-			}
-
 			r.Circle(dotWidth, x, y)
 			r.FillStroke()
 		}
 	}
 }
 
-// BoundedSeries draws a series that implements BoundedValuesProvider.
-func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, bbs BoundedValuesProvider, drawOffsetIndexes ...int) {
+// BoundedSeries draws a series that implements BoundedValueProvider.
+func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, bbs BoundedValueProvider, drawOffsetIndexes ...int) {
 	drawOffsetIndex := 0
 	if len(drawOffsetIndexes) > 0 {
 		drawOffsetIndex = drawOffsetIndexes[0]
@@ -94,7 +81,7 @@ func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, sty
 	cb := canvasBox.Bottom
 	cl := canvasBox.Left
 
-	v0x, v0y1, v0y2 := bbs.GetBoundedValues(0)
+	v0x, v0y1, v0y2 := bbs.GetBoundedValue(0)
 	x0 := cl + xrange.Translate(v0x)
 	y0 := cb - yrange.Translate(v0y1)
 
@@ -109,7 +96,7 @@ func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, sty
 	style.GetFillAndStrokeOptions().WriteToRenderer(r)
 	r.MoveTo(x0, y0)
 	for i := 1; i < bbs.Len(); i++ {
-		vx, vy1, vy2 = bbs.GetBoundedValues(i)
+		vx, vy1, vy2 = bbs.GetBoundedValue(i)
 
 		xvalues[i] = vx
 		y2values[i] = vy2
@@ -135,7 +122,7 @@ func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, sty
 }
 
 // HistogramSeries draws a value provider as boxes from 0.
-func (d draw) HistogramSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, vs ValuesProvider, barWidths ...int) {
+func (d draw) HistogramSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, vs ValueProvider, barWidths ...int) {
 	if vs.Len() == 0 {
 		return
 	}
@@ -152,7 +139,7 @@ func (d draw) HistogramSeries(r Renderer, canvasBox Box, xrange, yrange Range, s
 
 	//foreach datapoint, draw a box.
 	for index := 0; index < seriesLength; index++ {
-		vx, vy := vs.GetValues(index)
+		vx, vy := vs.GetValue(index)
 		y0 := yrange.Translate(0)
 		x := cl + xrange.Translate(vx)
 		y := yrange.Translate(vy)
@@ -296,10 +283,8 @@ func (d draw) TextWithin(r Renderer, text string, box Box, style Style) {
 	switch style.GetTextVerticalAlign() {
 	case TextVerticalAlignBottom, TextVerticalAlignBaseline: // i have to build better baseline handling into measure text
 		y = y - linesBox.Height()
-	case TextVerticalAlignMiddle:
-		y = y + (box.Height() >> 1) - (linesBox.Height() >> 1)
-	case TextVerticalAlignMiddleBaseline:
-		y = y + (box.Height() >> 1) - linesBox.Height()
+	case TextVerticalAlignMiddle, TextVerticalAlignMiddleBaseline:
+		y = (y - linesBox.Height()) >> 1
 	}
 
 	var tx, ty int

drawing/color.go

@@ -2,46 +2,27 @@ package drawing
 
 import (
 	"fmt"
-	"regexp"
 	"strconv"
-	"strings"
 )
 
-// Basic Colors from:
-// https://www.w3.org/wiki/CSS/Properties/color/keywords
 var (
 	// ColorTransparent is a fully transparent color.
-	ColorTransparent = Color{R: 255, G: 255, B: 255, A: 0}
+	ColorTransparent = Color{}
+
 	// ColorWhite is white.
 	ColorWhite = Color{R: 255, G: 255, B: 255, A: 255}
+
 	// ColorBlack is black.
 	ColorBlack = Color{R: 0, G: 0, B: 0, A: 255}
+
 	// ColorRed is red.
 	ColorRed = Color{R: 255, G: 0, B: 0, A: 255}
+
 	// ColorGreen is green.
-	ColorGreen = Color{R: 0, G: 128, B: 0, A: 255}
+	ColorGreen = Color{R: 0, G: 255, B: 0, A: 255}
+
 	// ColorBlue is blue.
 	ColorBlue = Color{R: 0, G: 0, B: 255, A: 255}
-	// ColorSilver is a known color.
-	ColorSilver = Color{R: 192, G: 192, B: 192, A: 255}
-	// ColorMaroon is a known color.
-	ColorMaroon = Color{R: 128, G: 0, B: 0, A: 255}
-	// ColorPurple is a known color.
-	ColorPurple = Color{R: 128, G: 0, B: 128, A: 255}
-	// ColorFuchsia is a known color.
-	ColorFuchsia = Color{R: 255, G: 0, B: 255, A: 255}
-	// ColorLime is a known color.
-	ColorLime = Color{R: 0, G: 255, B: 0, A: 255}
-	// ColorOlive is a known color.
-	ColorOlive = Color{R: 128, G: 128, B: 0, A: 255}
-	// ColorYellow is a known color.
-	ColorYellow = Color{R: 255, G: 255, B: 0, A: 255}
-	// ColorNavy is a known color.
-	ColorNavy = Color{R: 0, G: 0, B: 128, A: 255}
-	// ColorTeal is a known color.
-	ColorTeal = Color{R: 0, G: 128, B: 128, A: 255}
-	// ColorAqua is a known color.
-	ColorAqua = Color{R: 0, G: 255, B: 255, A: 255}
 )
 
 func parseHex(hex string) uint8 {
@@ -49,97 +30,8 @@ func parseHex(hex string) uint8 {
 	return uint8(v)
 }
 
-// ParseColor parses a color from a string.
-func ParseColor(rawColor string) Color {
-	if strings.HasPrefix(rawColor, "rgba") {
-		return ColorFromRGBA(rawColor)
-	}
-	if strings.HasPrefix(rawColor, "rgb") {
-		return ColorFromRGB(rawColor)
-	}
-	if strings.HasPrefix(rawColor, "#") {
-		return ColorFromHex(rawColor)
-	}
-	return ColorFromKnown(rawColor)
-}
-
-var rgbaexpr = regexp.MustCompile(`rgba\((?P<R>.+),(?P<G>.+),(?P<B>.+),(?P<A>.+)\)`)
-
-// ColorFromRGBA returns a color from an `rgba()` css function.
-func ColorFromRGBA(rgba string) (output Color) {
-	values := rgbaexpr.FindStringSubmatch(rgba)
-	for i, name := range rgbaexpr.SubexpNames() {
-		if i == 0 {
-			continue
-		}
-		if i >= len(values) {
-			break
-		}
-		switch name {
-		case "R":
-			value := strings.TrimSpace(values[i])
-			parsed, _ := strconv.ParseInt(value, 10, 16)
-			output.R = uint8(parsed)
-		case "G":
-			value := strings.TrimSpace(values[i])
-			parsed, _ := strconv.ParseInt(value, 10, 16)
-			output.G = uint8(parsed)
-		case "B":
-			value := strings.TrimSpace(values[i])
-			parsed, _ := strconv.ParseInt(value, 10, 16)
-			output.B = uint8(parsed)
-		case "A":
-			value := strings.TrimSpace(values[i])
-			parsed, _ := strconv.ParseFloat(value, 32)
-			if parsed > 1 {
-				parsed = 1
-			} else if parsed < 0 {
-				parsed = 0
-			}
-			output.A = uint8(parsed * 255)
-		}
-	}
-	return
-}
-
-var rgbexpr = regexp.MustCompile(`rgb\((?P<R>.+),(?P<G>.+),(?P<B>.+)\)`)
-
-// ColorFromRGB returns a color from an `rgb()` css function.
-func ColorFromRGB(rgb string) (output Color) {
-	output.A = 255
-	values := rgbexpr.FindStringSubmatch(rgb)
-	for i, name := range rgbaexpr.SubexpNames() {
-		if i == 0 {
-			continue
-		}
-		if i >= len(values) {
-			break
-		}
-		switch name {
-		case "R":
-			value := strings.TrimSpace(values[i])
-			parsed, _ := strconv.ParseInt(value, 10, 16)
-			output.R = uint8(parsed)
-		case "G":
-			value := strings.TrimSpace(values[i])
-			parsed, _ := strconv.ParseInt(value, 10, 16)
-			output.G = uint8(parsed)
-		case "B":
-			value := strings.TrimSpace(values[i])
-			parsed, _ := strconv.ParseInt(value, 10, 16)
-			output.B = uint8(parsed)
-		}
-	}
-	return
-}
-
 // ColorFromHex returns a color from a css hex code.
-//
-// NOTE: it will trim a leading '#' character if present.
 func ColorFromHex(hex string) Color {
-	if strings.HasPrefix(hex, "#") {
-		hex = strings.TrimPrefix(hex, "#")
-	}
 	var c Color
 	if len(hex) == 3 {
 		c.R = parseHex(string(hex[0])) * 0x11
@@ -154,46 +46,6 @@ func ColorFromHex(hex string) Color {
 	return c
 }
 
-// ColorFromKnown returns an internal color from a known (basic) color name.
-func ColorFromKnown(known string) Color {
-	switch strings.ToLower(known) {
-	case "transparent":
-		return ColorTransparent
-	case "white":
-		return ColorWhite
-	case "black":
-		return ColorBlack
-	case "red":
-		return ColorRed
-	case "blue":
-		return ColorBlue
-	case "green":
-		return ColorGreen
-	case "silver":
-		return ColorSilver
-	case "maroon":
-		return ColorMaroon
-	case "purple":
-		return ColorPurple
-	case "fuchsia":
-		return ColorFuchsia
-	case "lime":
-		return ColorLime
-	case "olive":
-		return ColorOlive
-	case "yellow":
-		return ColorYellow
-	case "navy":
-		return ColorNavy
-	case "teal":
-		return ColorTeal
-	case "aqua":
-		return ColorAqua
-	default:
-		return Color{}
-	}
-}
-
 // ColorFromAlphaMixedRGBA returns the system alpha mixed rgba values.
 func ColorFromAlphaMixedRGBA(r, g, b, a uint32) Color {
 	fa := float64(a) / 255.0
@@ -205,11 +57,6 @@ func ColorFromAlphaMixedRGBA(r, g, b, a uint32) Color {
 	return c
 }
 
-// ColorChannelFromFloat returns a normalized byte from a given float value.
-func ColorChannelFromFloat(v float64) uint8 {
-	return uint8(v * 255)
-}
-
 // Color is our internal color type because color.Color is bullshit.
 type Color struct {
 	R, G, B, A uint8

drawing/color_test.go

@@ -1,114 +1,53 @@
 package drawing
 
 import (
-	"fmt"
 	"testing"
 
 	"image/color"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	"github.com/blendlabs/go-assert"
 )
 
 func TestColorFromHex(t *testing.T) {
+	assert := assert.New(t)
+
 	white := ColorFromHex("FFFFFF")
-	testutil.AssertEqual(t, ColorWhite, white)
+	assert.Equal(ColorWhite, white)
 
 	shortWhite := ColorFromHex("FFF")
-	testutil.AssertEqual(t, ColorWhite, shortWhite)
+	assert.Equal(ColorWhite, shortWhite)
 
 	black := ColorFromHex("000000")
-	testutil.AssertEqual(t, ColorBlack, black)
+	assert.Equal(ColorBlack, black)
 
 	shortBlack := ColorFromHex("000")
-	testutil.AssertEqual(t, ColorBlack, shortBlack)
+	assert.Equal(ColorBlack, shortBlack)
 
 	red := ColorFromHex("FF0000")
-	testutil.AssertEqual(t, ColorRed, red)
+	assert.Equal(ColorRed, red)
 
 	shortRed := ColorFromHex("F00")
-	testutil.AssertEqual(t, ColorRed, shortRed)
+	assert.Equal(ColorRed, shortRed)
 
-	green := ColorFromHex("008000")
-	testutil.AssertEqual(t, ColorGreen, green)
+	green := ColorFromHex("00FF00")
+	assert.Equal(ColorGreen, green)
 
-	// shortGreen := ColorFromHex("0F0")
-	// testutil.AssertEqual(t, ColorGreen, shortGreen)
+	shortGreen := ColorFromHex("0F0")
+	assert.Equal(ColorGreen, shortGreen)
 
 	blue := ColorFromHex("0000FF")
-	testutil.AssertEqual(t, ColorBlue, blue)
+	assert.Equal(ColorBlue, blue)
 
 	shortBlue := ColorFromHex("00F")
-	testutil.AssertEqual(t, ColorBlue, shortBlue)
-}
-
-func TestColorFromHex_handlesHash(t *testing.T) {
-	withHash := ColorFromHex("#FF0000")
-	testutil.AssertEqual(t, ColorRed, withHash)
-
-	withoutHash := ColorFromHex("#FF0000")
-	testutil.AssertEqual(t, ColorRed, withoutHash)
+	assert.Equal(ColorBlue, shortBlue)
 }
 
 func TestColorFromAlphaMixedRGBA(t *testing.T) {
+	assert := assert.New(t)
+
 	black := ColorFromAlphaMixedRGBA(color.Black.RGBA())
-	testutil.AssertTrue(t, black.Equals(ColorBlack), black.String())
+	assert.True(black.Equals(ColorBlack), black.String())
 
 	white := ColorFromAlphaMixedRGBA(color.White.RGBA())
-	testutil.AssertTrue(t, white.Equals(ColorWhite), white.String())
-}
-
-func Test_ColorFromRGBA(t *testing.T) {
-	value := "rgba(192, 192, 192, 1.0)"
-	parsed := ColorFromRGBA(value)
-	testutil.AssertEqual(t, ColorSilver, parsed)
-
-	value = "rgba(192,192,192,1.0)"
-	parsed = ColorFromRGBA(value)
-	testutil.AssertEqual(t, ColorSilver, parsed)
-
-	value = "rgba(192,192,192,1.5)"
-	parsed = ColorFromRGBA(value)
-	testutil.AssertEqual(t, ColorSilver, parsed)
-}
-
-func TestParseColor(t *testing.T) {
-	testCases := [...]struct {
-		Input    string
-		Expected Color
-	}{
-		{"", Color{}},
-		{"white", ColorWhite},
-		{"WHITE", ColorWhite}, // caps!
-		{"black", ColorBlack},
-		{"red", ColorRed},
-		{"green", ColorGreen},
-		{"blue", ColorBlue},
-		{"silver", ColorSilver},
-		{"maroon", ColorMaroon},
-		{"purple", ColorPurple},
-		{"fuchsia", ColorFuchsia},
-		{"lime", ColorLime},
-		{"olive", ColorOlive},
-		{"yellow", ColorYellow},
-		{"navy", ColorNavy},
-		{"teal", ColorTeal},
-		{"aqua", ColorAqua},
-
-		{"rgba(192, 192, 192, 1.0)", ColorSilver},
-		{"rgba(192,192,192,1.0)", ColorSilver},
-		{"rgb(192, 192, 192)", ColorSilver},
-		{"rgb(192,192,192)", ColorSilver},
-
-		{"#FF0000", ColorRed},
-		{"#008000", ColorGreen},
-		{"#0000FF", ColorBlue},
-		{"#F00", ColorRed},
-		{"#080", Color{0, 136, 0, 255}},
-		{"#00F", ColorBlue},
-	}
-
-	for index, tc := range testCases {
-		actual := ParseColor(tc.Input)
-		testutil.AssertEqual(t, tc.Expected, actual, fmt.Sprintf("test case: %d -> %s", index, tc.Input))
-	}
+	assert.True(white.Equals(ColorWhite), white.String())
 }

drawing/curve_test.go

@@ -3,7 +3,7 @@ package drawing
 import (
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	assert "github.com/blendlabs/go-assert"
 )
 
 type point struct {
@@ -23,7 +23,7 @@ func (ml mockLine) Len() int {
 }
 
 func TestTraceQuad(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
 	// Quad
 	// x1, y1, cpx1, cpy2, x2, y2 float64
@@ -31,5 +31,5 @@ func TestTraceQuad(t *testing.T) {
 	quad := []float64{10, 20, 20, 20, 20, 10}
 	liner := &mockLine{}
 	TraceQuad(liner, quad, 0.5)
-	testutil.AssertNotZero(t, liner.Len())
+	assert.NotZero(liner.Len())
 }

ema_series.go

@@ -7,13 +7,6 @@ const (
 	DefaultEMAPeriod = 12
 )
 
-// Interface Assertions.
-var (
-	_ Series              = (*EMASeries)(nil)
-	_ FirstValuesProvider = (*EMASeries)(nil)
-	_ LastValuesProvider  = (*EMASeries)(nil)
-)
-
 // EMASeries is a computed series.
 type EMASeries struct {
 	Name  string
@@ -21,7 +14,7 @@ type EMASeries struct {
 	YAxis YAxisType
 
 	Period      int
-	InnerSeries ValuesProvider
+	InnerSeries ValueProvider
 
 	cache []float64
 }
@@ -59,36 +52,23 @@ func (ema EMASeries) GetSigma() float64 {
 	return 2.0 / (float64(ema.GetPeriod()) + 1)
 }
 
-// GetValues gets a value at a given index.
-func (ema *EMASeries) GetValues(index int) (x, y float64) {
+// GetValue gets a value at a given index.
+func (ema *EMASeries) GetValue(index int) (x, y float64) {
 	if ema.InnerSeries == nil {
 		return
 	}
 	if len(ema.cache) == 0 {
 		ema.ensureCachedValues()
 	}
-	vx, _ := ema.InnerSeries.GetValues(index)
+	vx, _ := ema.InnerSeries.GetValue(index)
 	x = vx
 	y = ema.cache[index]
 	return
 }
 
-// GetFirstValues computes the first moving average value.
-func (ema *EMASeries) GetFirstValues() (x, y float64) {
-	if ema.InnerSeries == nil {
-		return
-	}
-	if len(ema.cache) == 0 {
-		ema.ensureCachedValues()
-	}
-	x, _ = ema.InnerSeries.GetValues(0)
-	y = ema.cache[0]
-	return
-}
-
-// GetLastValues computes the last moving average value but walking back window size samples,
+// GetLastValue computes the last moving average value but walking back window size samples,
 // and recomputing the last moving average chunk.
-func (ema *EMASeries) GetLastValues() (x, y float64) {
+func (ema *EMASeries) GetLastValue() (x, y float64) {
 	if ema.InnerSeries == nil {
 		return
 	}
@@ -96,7 +76,7 @@ func (ema *EMASeries) GetLastValues() (x, y float64) {
 		ema.ensureCachedValues()
 	}
 	lastIndex := ema.InnerSeries.Len() - 1
-	x, _ = ema.InnerSeries.GetValues(lastIndex)
+	x, _ = ema.InnerSeries.GetValue(lastIndex)
 	y = ema.cache[lastIndex]
 	return
 }
@@ -106,7 +86,7 @@ func (ema *EMASeries) ensureCachedValues() {
 	ema.cache = make([]float64, seriesLength)
 	sigma := ema.GetSigma()
 	for x := 0; x < seriesLength; x++ {
-		_, y := ema.InnerSeries.GetValues(x)
+		_, y := ema.InnerSeries.GetValue(x)
 		if x == 0 {
 			ema.cache[x] = y
 			continue

ema_series_test.go

@@ -3,11 +3,11 @@ package chart
 import (
 	"testing"
 
-	"git.smarteching.com/zeni/go-chart/v2/testutil"
+	"github.com/blendlabs/go-assert"
 )
 
 var (
-	emaXValues = LinearRange(1.0, 50.0)
+	emaXValues = Sequence.Float64(1.0, 50.0)
 	emaYValues = []float64{
 		1, 2, 3, 4, 5, 4, 3, 2,
 		1, 2, 3, 4, 5, 4, 3, 2,
@@ -73,13 +73,13 @@ var (
 )
 
 func TestEMASeries(t *testing.T) {
-	// replaced new assertions helper
+	assert := assert.New(t)
 
-	mockSeries := mockValuesProvider{
+	mockSeries := mockValueProvider{
 		emaXValues,
 		emaYValues,
 	}
-	testutil.AssertEqual(t, 50, mockSeries.Len())
+	assert.Equal(50, mockSeries.Len())
 
 	ema := &EMASeries{
 		InnerSeries: mockSeries,
@@ -87,19 +87,19 @@ func TestEMASeries(t *testing.T) {
 	}
 
 	sig := ema.GetSigma()
-	testutil.AssertEqual(t, 2.0/(26.0+1), sig)
+	assert.Equal(2.0/(26.0+1), sig)
 
 	var yvalues []float64
 	for x := 0; x < ema.Len(); x++ {
-		_, y := ema.GetValues(x)
+		_, y := ema.GetValue(x)
 		yvalues = append(yvalues, y)
 	}
 
 	for index, yv := range yvalues {
-		testutil.AssertInDelta(t, yv, emaExpected[index], emaDelta)
+		assert.InDelta(yv, emaExpected[index], emaDelta)
 	}
 
-	lvx, lvy := ema.GetLastValues()
-	testutil.AssertEqual(t, 50.0, lvx)
-	testutil.AssertInDelta(t, lvy, emaExpected[49], emaDelta)
+	lvx, lvy := ema.GetLastValue()
+	assert.Equal(50.0, lvx)
+	assert.InDelta(lvy, emaExpected[49], emaDelta)
 }

examples/bar_chart/main.go

@@ -1,35 +0,0 @@
-package main
-
-//go:generate go run main.go
-
-import (
-	"os"
-
-	"git.smarteching.com/zeni/go-chart/v2"
-)
-
-func main() {
-	graph := chart.BarChart{
-		Title: "Test Bar Chart",
-		Background: chart.Style{
-			Padding: chart.Box{
-				Top: 40,
-			},
-		},
-		Height:   512,
-		BarWidth: 60,
-		Bars: []chart.Value{
-			{Value: 5.25, Label: "Blue"},
-			{Value: 4.88, Label: "Green"},
-			{Value: 4.74, Label: "Gray"},
-			{Value: 3.22, Label: "Orange"},
-			{Value: 3, Label: "Test"},
-			{Value: 2.27, Label: "??"},
-			{Value: 1, Label: "!!"},
-		},
-	}
-
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	graph.Render(chart.PNG, f)
-}

examples/bar_chart_base_value/main.go

@@ -1,62 +0,0 @@
-package main
-
-//go:generate go run main.go
-
-import (
-	"os"
-
-	"git.smarteching.com/zeni/go-chart/v2"
-	"git.smarteching.com/zeni/go-chart/v2/drawing"
-)
-
-func main() {
-	profitStyle := chart.Style{
-		FillColor:   drawing.ColorFromHex("13c158"),
-		StrokeColor: drawing.ColorFromHex("13c158"),
-		StrokeWidth: 0,
-	}
-
-	lossStyle := chart.Style{
-		FillColor:   drawing.ColorFromHex("c11313"),
-		StrokeColor: drawing.ColorFromHex("c11313"),
-		StrokeWidth: 0,
-	}
-
-	sbc := chart.BarChart{
-		Title: "Bar Chart Using BaseValue",
-		Background: chart.Style{
-			Padding: chart.Box{
-				Top: 40,
-			},
-		},
-		Height:   512,
-		BarWidth: 60,
-		YAxis: chart.YAxis{
-			Ticks: []chart.Tick{
-				{Value: -4.0, Label: "-4"},
-				{Value: -2.0, Label: "-2"},
-				{Value: 0, Label: "0"},
-				{Value: 2.0, Label: "2"},
-				{Value: 4.0, Label: "4"},
-				{Value: 6.0, Label: "6"},
-				{Value: 8.0, Label: "8"},
-				{Value: 10.0, Label: "10"},
-				{Value: 12.0, Label: "12"},
-			},
-		},
-		UseBaseValue: true,
-		BaseValue:    0.0,
-		Bars: []chart.Value{
-			{Value: 10.0, Style: profitStyle, Label: "Profit"},
-			{Value: 12.0, Style: profitStyle, Label: "More Profit"},
-			{Value: 8.0, Style: profitStyle, Label: "Still Profit"},
-			{Value: -4.0, Style: lossStyle, Label: "Loss!"},
-			{Value: 3.0, Style: profitStyle, Label: "Phew Ok"},
-			{Value: -2.0, Style: lossStyle, Label: "Oh No!"},
-		},
-	}
-
-	f, _ := os.Create("output.png")
-	defer f.Close()
-	sbc.Render(chart.PNG, f)
-}