switching to generators

examples/scatter/main.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	_ "net/http/pprof"
+
+	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/drawing"
+)
+
+func drawChart(res http.ResponseWriter, req *http.Request) {
+
+	viridisByY := func(xr, yr chart.Range, index int, x, y float64) drawing.Color {
+		return chart.Viridis(y, yr.GetMin(), yr.GetMax())
+	}
+
+	graph := chart.Chart{
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				Style: chart.Style{
+					StrokeWidth:      chart.Disabled,
+					DotWidth:         5,
+					DotColorProvider: viridisByY,
+				},
+				XValues: chart.Seq{Sequence: chart.NewLinearSequence().WithStart(0).WithEnd(127)}.Values(),
+				YValues: chart.Seq{Sequence: chart.NewRandomSequence().WithLen(128).WithMin(0).WithMax(1024)}.Values(),
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", chart.ContentTypePNG)
+	err := graph.Render(chart.PNG, res)
+	if err != nil {
+		log.Println(err.Error())
+	}
+}
+
+func unit(res http.ResponseWriter, req *http.Request) {
+	graph := chart.Chart{
+		Height: 50,
+		Width:  50,
+		Canvas: chart.Style{
+			Padding: chart.BoxZero,
+		},
+		Background: chart.Style{
+			Padding: chart.BoxZero,
+		},
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: chart.Seq{Sequence: chart.NewLinearSequence().WithStart(0).WithEnd(4)}.Values(),
+				YValues: chart.Seq{Sequence: chart.NewLinearSequence().WithStart(0).WithEnd(4)}.Values(),
+			},
+		},
+	}
+
+	res.Header().Set("Content-Type", chart.ContentTypePNG)
+	err := graph.Render(chart.PNG, res)
+	if err != nil {
+		log.Println(err.Error())
+	}
+}
+
+func main() {
+	http.HandleFunc("/", drawChart)
+	http.HandleFunc("/unit", unit)
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}