package main import ( "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 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) }) 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, 3, 9, 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, }, }, 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) }