package main import ( "fmt" "net/http" "github.com/wcharczuk/go-chart" ) func drawChart(res http.ResponseWriter, req *http.Request) { /* In this example we use a custom `ValueFormatter` for the y axis, letting us specify how to format text of the y-axis ticks. You can also do this for the x-axis, or the secondary y-axis. This example also shows what the chart looks like with the x-axis left off or not shown. */ graph := chart.Chart{ YAxis: chart.YAxis{ Style: chart.StyleShow(), ValueFormatter: func(v interface{}) string { if vf, isFloat := v.(float64); isFloat { return fmt.Sprintf("%0.6f", vf) } return "" }, }, Series: []chart.Series{ chart.ContinuousSeries{ XValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0}, YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0}, }, }, } res.Header().Set("Content-Type", "image/png") graph.Render(chart.PNG, res) } func main() { http.HandleFunc("/", drawChart) http.ListenAndServe(":8080", nil) }