Function Example_writerToCanvas

vg/example_test.go:152–189

()

}

func Example_writerToCanvas() {
	p := plot.New()
	p.Title.Text = "cos(x)"
	p.X.Label.Text = "x"
	p.Y.Label.Text = "f(x)"

	p.X.Min = -2 * math.Pi
	p.X.Max = +2 * math.Pi

	fct := plotter.NewFunction(func(x float64) float64 {
		return math.Cos(x)
	})
	fct.Color = color.RGBA{B: 255, A: 255}

	p.Add(fct, plotter.NewGrid())

	c := vgimg.PngCanvas{
		Canvas: vgimg.New(10*vg.Centimeter, 5*vg.Centimeter),
	}
	p.Draw(draw.New(c))

	// Save image.
	f, err := os.Create("testdata/cosine.png")
	if err != nil {
		log.Fatalf("could not create output image file: %+v", err)
	}
	defer f.Close()

	_, err = c.WriteTo(f)
	if err != nil {
		log.Fatalf("could not encode image to PNG: %+v", err)
	}

	err = f.Close()
	if err != nil {
		log.Fatalf("could not close output image file: %+v", err)
	}
}