package main import ( "net/http" "time" "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 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{ time.Now().AddDate(0, 0, -10), time.Now().AddDate(0, 0, -9), time.Now().AddDate(0, 0, -8), time.Now().AddDate(0, 0, -7), time.Now().AddDate(0, 0, -6), time.Now().AddDate(0, 0, -5), time.Now().AddDate(0, 0, -4), time.Now().AddDate(0, 0, -3), time.Now().AddDate(0, 0, -2), time.Now().AddDate(0, 0, -1), time.Now(), }, YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0}, }, }, } res.Header().Set("Content-Type", "image/png") graph.Render(chart.PNG, res) } func drawCustomChart(res http.ResponseWriter, req *http.Request) { /* This is basically the other timeseries example, except we switch to hour intervals and specify a different formatter from default for the xaxis tick labels. */ graph := chart.Chart{ XAxis: chart.XAxis{ Style: chart.Style{ Show: true, }, ValueFormatter: chart.TimeHourValueFormatter, }, Series: []chart.Series{ chart.TimeSeries{ XValues: []time.Time{ time.Now().Add(-10 * time.Hour), time.Now().Add(-9 * time.Hour), time.Now().Add(-8 * time.Hour), time.Now().Add(-7 * time.Hour), time.Now().Add(-6 * time.Hour), time.Now().Add(-5 * time.Hour), time.Now().Add(-4 * time.Hour), time.Now().Add(-3 * time.Hour), time.Now().Add(-2 * time.Hour), time.Now().Add(-1 * time.Hour), time.Now(), }, YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0}, }, }, } res.Header().Set("Content-Type", "image/png") graph.Render(chart.PNG, res) } func main() { http.HandleFunc("/", drawChart) http.HandleFunc("/favico.ico", func(res http.ResponseWriter, req *http.Request) { res.Write([]byte{}) }) http.HandleFunc("/custom", drawCustomChart) http.ListenAndServe(":8080", nil) }