basics of stacked bar.

This commit is contained in:
Will Charczuk 2016-07-28 18:51:55 -07:00
parent 020ec8f4a4
commit a1fb284797
8 changed files with 272 additions and 25 deletions

View file

@ -463,7 +463,7 @@ func (c Chart) styleDefaultsCanvas() Style {
}
func (c Chart) styleDefaultsSeries(seriesIndex int) Style {
strokeColor := GetDefaultSeriesStrokeColor(seriesIndex)
strokeColor := GetDefaultColor(seriesIndex)
return Style{
StrokeColor: strokeColor,
StrokeWidth: DefaultStrokeWidth,

View file

@ -159,16 +159,16 @@ var (
DashArrayDashesLarge = []int{10, 10}
)
// GetDefaultSeriesStrokeColor returns a color from the default list by index.
// GetDefaultColor returns a color from the default list by index.
// NOTE: the index will wrap around (using a modulo).
func GetDefaultSeriesStrokeColor(index int) drawing.Color {
func GetDefaultColor(index int) drawing.Color {
finalIndex := index % len(DefaultColors)
return DefaultColors[finalIndex]
}
// GetDefaultPieChartValueColor returns a color from the default list by index.
// GetAlternateColor returns a color from the default list by index.
// NOTE: the index will wrap around (using a modulo).
func GetDefaultPieChartValueColor(index int) drawing.Color {
func GetAlternateColor(index int) drawing.Color {
finalIndex := index % len(DefaultAlternateColors)
return DefaultAlternateColors[finalIndex]
}

View file

@ -14,13 +14,13 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
FillColor: chart.ColorLightGray,
},
Values: []chart.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: "!!"},
{Value: 5, Label: "Blue"},
{Value: 5, Label: "Green"},
{Value: 4, Label: "Gray"},
{Value: 4, Label: "Orange"},
{Value: 3, Label: "Test"},
{Value: 3, Label: "??"},
{Value: 1, Label: "!!"},
},
}

View file

@ -0,0 +1,48 @@
package main
import (
"fmt"
"log"
"net/http"
"github.com/wcharczuk/go-chart"
)
func drawChart(res http.ResponseWriter, req *http.Request) {
sbc := chart.StackedBarChart{
Background: chart.Style{
Padding: chart.Box{Top: 50, Left: 50, Right: 50, Bottom: 50},
},
Bars: []chart.StackedBar{
{
Values: []chart.Value{
{Value: 5, Label: "Blue"},
{Value: 5, Label: "Green"},
{Value: 4, Label: "Gray"},
{Value: 4, Label: "Orange"},
{Value: 3, Label: "Test"},
{Value: 3, Label: "??"},
{Value: 1, Label: "!!"},
},
},
{
Values: []chart.Value{
{Value: 10, Label: "Blue"},
{Value: 5, Label: "Green"},
{Value: 1, Label: "Gray"},
},
},
},
}
res.Header().Set("Content-Type", "image/svg+xml")
err := sbc.Render(chart.SVG, res)
if err != nil {
fmt.Printf("Error rendering chart: %v\n", err)
}
}
func main() {
http.HandleFunc("/", drawChart)
log.Fatal(http.ListenAndServe(":8080", nil))
}

View file

@ -217,7 +217,7 @@ func (pc PieChart) stylePieChartValue(index int) Style {
return Style{
StrokeColor: ColorWhite,
StrokeWidth: 5.0,
FillColor: GetDefaultPieChartValueColor(index),
FillColor: GetAlternateColor(index),
FontSize: 24.0,
FontColor: ColorWhite,
Font: pc.GetFont(),
@ -232,16 +232,6 @@ func (pc PieChart) styleDefaultsBackground() Style {
}
}
func (pc PieChart) styleDefaultsSeries(seriesIndex int) Style {
strokeColor := GetDefaultSeriesStrokeColor(seriesIndex)
return Style{
StrokeColor: strokeColor,
StrokeWidth: DefaultStrokeWidth,
Font: pc.GetFont(),
FontSize: DefaultFontSize,
}
}
func (pc PieChart) styleDefaultsElements() Style {
return Style{
Font: pc.GetFont(),

209
stacked_bar_chart.go Normal file
View file

@ -0,0 +1,209 @@
package chart
import (
"errors"
"io"
"github.com/golang/freetype/truetype"
)
// StackedBar is a bar within a StackedBarChart.
type StackedBar struct {
Name string
Width int
Values []Value
}
// GetWidth returns the width of the bar.
func (sb StackedBar) GetWidth() int {
if sb.Width == 0 {
return 20
}
return sb.Width
}
// StackedBarChart is a chart that draws sections of a bar based on percentages.
type StackedBarChart struct {
Title string
TitleStyle Style
Width int
Height int
DPI float64
Background Style
Canvas Style
BarSpacing int
Font *truetype.Font
defaultFont *truetype.Font
Bars []StackedBar
Elements []Renderable
}
// GetDPI returns the dpi for the chart.
func (sbc StackedBarChart) GetDPI(defaults ...float64) float64 {
if sbc.DPI == 0 {
if len(defaults) > 0 {
return defaults[0]
}
return DefaultDPI
}
return sbc.DPI
}
// GetFont returns the text font.
func (sbc StackedBarChart) GetFont() *truetype.Font {
if sbc.Font == nil {
return sbc.defaultFont
}
return sbc.Font
}
// GetWidth returns the chart width or the default value.
func (sbc StackedBarChart) GetWidth() int {
if sbc.Width == 0 {
return DefaultChartWidth
}
return sbc.Width
}
// GetHeight returns the chart height or the default value.
func (sbc StackedBarChart) GetHeight() int {
if sbc.Height == 0 {
return DefaultChartWidth
}
return sbc.Height
}
// GetBarSpacing returns the spacing between bars.
func (sbc StackedBarChart) GetBarSpacing() int {
if sbc.BarSpacing == 0 {
return 100
}
return sbc.BarSpacing
}
// Render renders the chart with the given renderer to the given io.Writer.
func (sbc StackedBarChart) Render(rp RendererProvider, w io.Writer) error {
if len(sbc.Bars) == 0 {
return errors.New("Please provide at least one bar.")
}
r, err := rp(sbc.GetWidth(), sbc.GetHeight())
if err != nil {
return err
}
if sbc.Font == nil {
defaultFont, err := GetDefaultFont()
if err != nil {
return err
}
sbc.defaultFont = defaultFont
}
r.SetDPI(sbc.GetDPI(DefaultDPI))
canvasBox := sbc.getAdjustedCanvasBox(sbc.getDefaultCanvasBox())
sbc.drawBars(r, canvasBox)
sbc.drawTitle(r)
for _, a := range sbc.Elements {
a(r, canvasBox, sbc.styleDefaultsElements())
}
return r.Save(w)
}
func (sbc StackedBarChart) drawBars(r Renderer, canvasBox Box) {
xoffset := canvasBox.Left
for _, bar := range sbc.Bars {
sbc.drawBar(r, canvasBox, xoffset, bar)
xoffset += sbc.GetBarSpacing()
}
}
func (sbc StackedBarChart) drawBar(r Renderer, canvasBox Box, xoffset int, bar StackedBar) int {
bxl := xoffset
bxr := xoffset + bar.GetWidth()
normalizedBarComponents := Values(bar.Values).Normalize()
yoffset := canvasBox.Top
for index, bv := range normalizedBarComponents {
barHeight := int(bv.Value * float64(canvasBox.Height()))
barBox := Box{Top: yoffset, Left: bxl, Right: bxr, Bottom: yoffset + barHeight}
DrawBox(r, barBox, bv.Style.InheritFrom(sbc.styleDefaultsStackedBarValue(index)))
yoffset += barHeight
}
return bxr
}
func (sbc StackedBarChart) drawTitle(r Renderer) {
if len(sbc.Title) > 0 && sbc.TitleStyle.Show {
r.SetFont(sbc.TitleStyle.GetFont(sbc.GetFont()))
r.SetFontColor(sbc.TitleStyle.GetFontColor(DefaultTextColor))
titleFontSize := sbc.TitleStyle.GetFontSize(DefaultTitleFontSize)
r.SetFontSize(titleFontSize)
textBox := r.MeasureText(sbc.Title)
textWidth := textBox.Width()
textHeight := textBox.Height()
titleX := (sbc.GetWidth() >> 1) - (textWidth >> 1)
titleY := sbc.TitleStyle.Padding.GetTop(DefaultTitleTop) + textHeight
r.Text(sbc.Title, titleX, titleY)
}
}
func (sbc StackedBarChart) getDefaultCanvasBox() Box {
return sbc.Box()
}
func (sbc StackedBarChart) getAdjustedCanvasBox(canvasBox Box) Box {
var totalWidth int
for index, bar := range sbc.Bars {
totalWidth += bar.GetWidth()
if index < len(sbc.Bars)-1 {
totalWidth += sbc.GetBarSpacing()
}
}
return canvasBox.OuterConstrain(sbc.Box(), Box{
Top: canvasBox.Top,
Left: canvasBox.Left,
Right: canvasBox.Left + totalWidth,
Bottom: canvasBox.Bottom,
})
}
// Box returns the chart bounds as a box.
func (sbc StackedBarChart) Box() Box {
dpr := sbc.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
dpb := sbc.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
return Box{
Top: sbc.Background.Padding.GetTop(DefaultBackgroundPadding.Top),
Left: sbc.Background.Padding.GetLeft(DefaultBackgroundPadding.Left),
Right: sbc.GetWidth() - dpr,
Bottom: sbc.GetHeight() - dpb,
}
}
func (sbc StackedBarChart) styleDefaultsStackedBarValue(index int) Style {
return Style{
StrokeColor: GetAlternateColor(index),
StrokeWidth: 3.0,
FillColor: GetAlternateColor(index),
}
}
func (sbc StackedBarChart) styleDefaultsElements() Style {
return Style{
Font: sbc.GetFont(),
}
}

View file

@ -109,7 +109,7 @@ func Normalize(values ...float64) []float64 {
}
output := make([]float64, len(values))
for x, v := range values {
output[x] = RoundDown(v/total, 0.001)
output[x] = RoundDown(v/total, 0.00001)
}
return output
}

View file

@ -32,7 +32,7 @@ func (vs Values) Normalize() []Value {
output[index] = Value{
Style: v.Style,
Label: v.Label,
Value: RoundDown(v.Value/total, 0.001),
Value: RoundDown(v.Value/total, 0.00001),
}
}
return output