Function ExampleContour

plotter/contour_example_test.go:22–58

()

)

func ExampleContour() {
	rnd := rand.New(rand.NewPCG(1234, 1234))

	const stddev = 2
	data := make([]float64, 6400)
	for i := range data {
		r := float64(i/80) - 40
		c := float64(i%80) - 40

		data[i] = rnd.NormFloat64()*stddev + math.Hypot(r, c)
	}

	var (
		grid   = unitGrid{mat.NewDense(80, 80, data)}
		levels = []float64{-1, 3, 7, 9, 13, 15, 19, 23, 27, 31}

		c = plotter.NewContour(
			grid,
			levels,
			palette.Rainbow(10, palette.Blue, palette.Red, 1, 1, 1),
		)
	)

	p := plot.New()
	p.Title.Text = "Contour"
	p.X.Padding = 0
	p.Y.Padding = 0
	p.X.Max = 79.5
	p.Y.Max = 79.5

	p.Add(c)

	err := p.Save(10*vg.Centimeter, 10*vg.Centimeter, "testdata/contour_"+runtime.GOARCH+".png")
	if err != nil {
		log.Fatalf("could not save plot: %+v", err)
	}
}

type unitGrid struct{ mat.Matrix }