Adding upstream version 2.1.2.

Signed-off-by: Daniel Baumann <daniel@debian.org>

examples/request_timings/main.go

@@ -0,0 +1,133 @@
+package main
+
+//go:generate go run main.go
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/wcharczuk/go-chart/v2"
+)
+
+func main() {
+	log := chart.NewLogger()
+	drawChart(log)
+}
+
+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.ReadLines("requests.csv", func(line string) error {
+		parts := chart.SplitCSV(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)
+		return nil
+	})
+	if err != nil {
+		fmt.Println(err.Error())
+	}
+	return xvalues, yvalues
+}
+
+func releases() []chart.GridLine {
+	return []chart.GridLine{
+		{Value: chart.TimeToFloat64(time.Date(2016, 8, 1, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.TimeToFloat64(time.Date(2016, 8, 2, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.TimeToFloat64(time.Date(2016, 8, 2, 15, 30, 0, 0, time.UTC))},
+		{Value: chart.TimeToFloat64(time.Date(2016, 8, 4, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.TimeToFloat64(time.Date(2016, 8, 5, 9, 30, 0, 0, time.UTC))},
+		{Value: chart.TimeToFloat64(time.Date(2016, 8, 6, 9, 30, 0, 0, time.UTC))},
+	}
+}
+
+func drawChart(log chart.Logger) http.HandlerFunc {
+	return func(res http.ResponseWriter, req *http.Request) {
+		xvalues, yvalues := readData()
+		mainSeries := chart.TimeSeries{
+			Name: "Prod Request Timings",
+			Style: chart.Style{
+				StrokeColor: chart.ColorBlue,
+				FillColor:   chart.ColorBlue.WithAlpha(100),
+			},
+			XValues: xvalues,
+			YValues: yvalues,
+		}
+
+		linreg := &chart.LinearRegressionSeries{
+			Name: "Linear Regression",
+			Style: chart.Style{
+				StrokeColor:     chart.ColorAlternateBlue,
+				StrokeDashArray: []float64{5.0, 5.0},
+			},
+			InnerSeries: mainSeries,
+		}
+
+		sma := &chart.SMASeries{
+			Name: "SMA",
+			Style: chart.Style{
+				StrokeColor:     chart.ColorRed,
+				StrokeDashArray: []float64{5.0, 5.0},
+			},
+			InnerSeries: mainSeries,
+		}
+
+		graph := chart.Chart{
+			Log:    log,
+			Width:  1280,
+			Height: 720,
+			Background: chart.Style{
+				Padding: chart.Box{
+					Top: 50,
+				},
+			},
+			YAxis: chart.YAxis{
+				Name: "Elapsed Millis",
+				TickStyle: chart.Style{
+					TextRotationDegrees: 45.0,
+				},
+				ValueFormatter: func(v interface{}) string {
+					return fmt.Sprintf("%d ms", int(v.(float64)))
+				},
+			},
+			XAxis: chart.XAxis{
+				ValueFormatter: chart.TimeHourValueFormatter,
+				GridMajorStyle: chart.Style{
+					StrokeColor: chart.ColorAlternateGray,
+					StrokeWidth: 1.0,
+				},
+				GridLines: releases(),
+			},
+			Series: []chart.Series{
+				mainSeries,
+				linreg,
+				chart.LastValueAnnotationSeries(linreg),
+				sma,
+				chart.LastValueAnnotationSeries(sma),
+			},
+		}
+
+		graph.Elements = []chart.Renderable{chart.LegendThin(&graph)}
+
+		f, _ := os.Create("output.png")
+		defer f.Close()
+		graph.Render(chart.PNG, f)
+	}
+}