Helper API refactor (#40)

* api cleaup

* updates

* wtf

* updates

* snapshot.

* tweaks

* snapshot

* api tweaks.

* updates

* updates

* updates

* changes.

* updates

* updates

* sequence => seq

* dont need to use curl, just using wget

* fixing examples

_examples/benchmark_line_charts/main.go

@@ -20,12 +20,18 @@ func drawLargeChart(res http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		numSeriesInt64 = int64(1)
 	}
+	if numSeriesInt64 == 0 {
+		numSeriesInt64 = 1
+	}
 	numSeries := int(numSeriesInt64)
 
 	numValuesInt64, err := strconv.ParseInt(r.FormValue("values"), 10, 64)
 	if err != nil {
 		numValuesInt64 = int64(100)
 	}
+	if numValuesInt64 == 0 {
+		numValuesInt64 = int64(100)
+	}
 	numValues := int(numValuesInt64)
 
 	series := make([]chart.Series, numSeries)

_examples/custom_padding/main.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/wcharczuk/go-chart"
 	"github.com/wcharczuk/go-chart/drawing"
+	"github.com/wcharczuk/go-chart/seq"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
@@ -30,8 +31,8 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
-				XValues: chart.Sequence.Float64(1.0, 100.0),
-				YValues: chart.Sequence.Random(100.0, 256.0),
+				XValues: seq.Range(1.0, 100.0),
+				YValues: seq.RandomValuesWithMax(100, 512),
 			},
 		},
 	}
@@ -57,8 +58,8 @@ func drawChartDefault(res http.ResponseWriter, req *http.Request) {
 		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
-				XValues: chart.Sequence.Float64(1.0, 100.0),
-				YValues: chart.Sequence.Random(100.0, 256.0),
+				XValues: seq.Range(1.0, 100.0),
+				YValues: seq.RandomValuesWithMax(100, 512),
 			},
 		},
 	}

_examples/linear_regression/main.go

@@ -4,19 +4,20 @@ import (
 	"net/http"
 
 	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/seq"
 )
 
 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.
+		InnerSeries only needs to implement `ValuesProvider`, 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.
+		XValues: seq.Range(1.0, 100.0),                 //generates a []float64 from 1.0 to 100.0 in 1.0 step increments, or 100 elements.
+		YValues: seq.RandomValuesWithAverage(100, 100), //generates a []float64 randomly from 0 to 100 with 100 elements.
 	}
 
 	// note we create a LinearRegressionSeries series by assignin the inner series.

_examples/market_hours/main.go

@@ -4,13 +4,15 @@ import (
 	"net/http"
 
 	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/seq"
+	"github.com/wcharczuk/go-chart/util"
 )
 
 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)
+	start := util.Date.Date(2016, 7, 01, util.Date.Eastern())
+	end := util.Date.Date(2016, 07, 21, util.Date.Eastern())
+	xv := seq.Time.MarketHours(start, end, util.NYSEOpen(), util.NYSEClose(), util.Date.IsNYSEHoliday)
+	yv := seq.New(seq.NewRandom().WithLen(len(xv)).WithAverage(200).WithScale(10)).Array()
 
 	graph := chart.Chart{
 		XAxis: chart.XAxis{
@@ -18,9 +20,9 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 			TickPosition:   chart.TickPositionBetweenTicks,
 			ValueFormatter: chart.TimeHourValueFormatter,
 			Range: &chart.MarketHoursRange{
-				MarketOpen:      chart.NYSEOpen,
-				MarketClose:     chart.NYSEClose,
-				HolidayProvider: chart.Date.IsNYSEHoliday,
+				MarketOpen:      util.NYSEOpen(),
+				MarketClose:     util.NYSEClose(),
+				HolidayProvider: util.Date.IsNYSEHoliday,
 			},
 		},
 		YAxis: chart.YAxis{

_examples/min_max/main.go

@@ -4,13 +4,14 @@ import (
 	"net/http"
 
 	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/seq"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
 	mainSeries := chart.ContinuousSeries{
 		Name:    "A test series",
-		XValues: chart.Sequence.Float64(1.0, 100.0),
-		YValues: chart.Sequence.RandomWithAverage(100, 100, 50),
+		XValues: seq.Range(1.0, 100.0),
+		YValues: seq.New(seq.NewRandom().WithLen(100).WithAverage(100).WithScale(50)).Array(),
 	}
 
 	minSeries := &chart.MinSeries{

_examples/poly_regression/main.go

@@ -4,19 +4,20 @@ import (
 	"net/http"
 
 	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/seq"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	/*
 		In this example we add a new type of series, a `PolynomialRegressionSeries` that takes another series as a required argument.
-		InnerSeries only needs to implement `ValueProvider`, so really you could chain `PolynomialRegressionSeries` together if you wanted.
+		InnerSeries only needs to implement `ValuesProvider`, so really you could chain `PolynomialRegressionSeries` 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.
+		XValues: seq.Range(1.0, 100.0),                 //generates a []float64 from 1.0 to 100.0 in 1.0 step increments, or 100 elements.
+		YValues: seq.RandomValuesWithAverage(100, 100), //generates a []float64 randomly from 0 to 100 with 100 elements.
 	}
 
 	polyRegSeries := &chart.PolynomialRegressionSeries{

_examples/request_timings/main.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/wcharczuk/go-chart"
+	util "github.com/wcharczuk/go-chart/util"
 )
 
 func parseInt(str string) int {
@@ -23,7 +24,7 @@ func parseFloat64(str string) float64 {
 func readData() ([]time.Time, []float64) {
 	var xvalues []time.Time
 	var yvalues []float64
-	err := chart.File.ReadByLines("requests.csv", func(line string) {
+	err := util.File.ReadByLines("requests.csv", func(line string) error {
 		parts := strings.Split(line, ",")
 		year := parseInt(parts[0])
 		month := parseInt(parts[1])
@@ -32,6 +33,7 @@ func readData() ([]time.Time, []float64) {
 		elapsedMillis := parseFloat64(parts[4])
 		xvalues = append(xvalues, time.Date(year, time.Month(month), day, hour, 0, 0, 0, time.UTC))
 		yvalues = append(yvalues, elapsedMillis)
+		return nil
 	})
 	if err != nil {
 		fmt.Println(err.Error())
@@ -41,12 +43,12 @@ func readData() ([]time.Time, []float64) {
 
 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))},
+		{Value: util.Time.ToFloat64(time.Date(2016, 8, 1, 9, 30, 0, 0, time.UTC))},
+		{Value: util.Time.ToFloat64(time.Date(2016, 8, 2, 9, 30, 0, 0, time.UTC))},
+		{Value: util.Time.ToFloat64(time.Date(2016, 8, 2, 15, 30, 0, 0, time.UTC))},
+		{Value: util.Time.ToFloat64(time.Date(2016, 8, 4, 9, 30, 0, 0, time.UTC))},
+		{Value: util.Time.ToFloat64(time.Date(2016, 8, 5, 9, 30, 0, 0, time.UTC))},
+		{Value: util.Time.ToFloat64(time.Date(2016, 8, 6, 9, 30, 0, 0, time.UTC))},
 	}
 }
 
@@ -125,8 +127,8 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	graph.Elements = []chart.Renderable{chart.LegendThin(&graph)}
 
-	res.Header().Set("Content-Type", chart.ContentTypeSVG)
-	graph.Render(chart.SVG, res)
+	res.Header().Set("Content-Type", chart.ContentTypePNG)
+	graph.Render(chart.PNG, res)
 }
 
 func main() {

_examples/scatter/main.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/wcharczuk/go-chart"
 	"github.com/wcharczuk/go-chart/drawing"
+	"github.com/wcharczuk/go-chart/seq"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
@@ -25,8 +26,8 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 					DotWidth:         5,
 					DotColorProvider: viridisByY,
 				},
-				XValues: chart.Sequence.Random(128, 1024),
-				YValues: chart.Sequence.Random(128, 1024),
+				XValues: seq.Range(0, 127),
+				YValues: seq.New(seq.NewRandom().WithLen(128).WithMax(1024)).Array(),
 			},
 		},
 	}
@@ -50,8 +51,8 @@ func unit(res http.ResponseWriter, req *http.Request) {
 		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
-				XValues: chart.Sequence.Float64(0, 4, 1),
-				YValues: chart.Sequence.Float64(0, 4, 1),
+				XValues: seq.RangeWithStep(0, 4, 1),
+				YValues: seq.RangeWithStep(0, 4, 1),
 			},
 		},
 	}

_examples/simple_moving_average/main.go

@@ -4,19 +4,15 @@ import (
 	"net/http"
 
 	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/seq"
 )
 
 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.
+		XValues: seq.Range(1.0, 100.0),             //generates a []float64 from 1.0 to 100.0 in 1.0 step increments, or 100 elements.
+		YValues: seq.RandomValuesWithMax(100, 100), //generates a []float64 randomly from 0 to 100 with 100 elements.
 	}
 
 	// note we create a SimpleMovingAverage series by assignin the inner series.

_examples/twoaxis/main.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/wcharczuk/go-chart"
+	util "github.com/wcharczuk/go-chart/util"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
@@ -23,7 +24,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 			TickPosition: chart.TickPositionBetweenTicks,
 			ValueFormatter: func(v interface{}) string {
 				typed := v.(float64)
-				typedDate := chart.Time.FromFloat64(typed)
+				typedDate := util.Time.FromFloat64(typed)
 				return fmt.Sprintf("%d-%d\n%d", typedDate.Month(), typedDate.Day(), typedDate.Year())
 			},
 		},

_examples/twopoint/main.go

@@ -4,8 +4,8 @@ import (
 	"bytes"
 	"log"
 	"os"
-	//"time"
-	"github.com/wcharczuk/go-chart" //exposes "chart"
+
+	"github.com/wcharczuk/go-chart"
 )
 
 func main() {
@@ -18,8 +18,6 @@ func main() {
 		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},
 	}