// Example_functions draws some functions.
func Example_functions() *plot.Plot {
p, err := plot.New()
if err != nil {
panic(err)
}
p.Title.Text = "Functions"
p.X.Label.Text = "X"
p.Y.Label.Text = "Y"
quad := plotter.NewFunction(func(x float64) float64 { return x * x })
quad.Color = color.RGBA{B: 255, A: 255}
exp := plotter.NewFunction(func(x float64) float64 { return math.Pow(2, x) })
exp.Dashes = []vg.Length{vg.Points(2), vg.Points(2)}
exp.Width = vg.Points(2)
exp.Color = color.RGBA{G: 255, A: 255}
sin := plotter.NewFunction(func(x float64) float64 { return 10*math.Sin(x) + 50 })
sin.Dashes = []vg.Length{vg.Points(4), vg.Points(5)}
sin.Width = vg.Points(4)
sin.Color = color.RGBA{R: 255, A: 255}
p.Add(quad, exp, sin)
p.Legend.Add("x^2", quad)
p.Legend.Add("2^x", exp)
p.Legend.Add("10*sin(x)+50", sin)
p.Legend.ThumbnailWidth = vg.Inches(0.5)
p.X.Min = 0
p.X.Max = 10
p.Y.Min = 0
p.Y.Max = 100
return p
}
// An example of making a histogram.
func Example_histogram() *plot.Plot {
rand.Seed(int64(0))
n := 10000
vals := make(plotter.Values, n)
for i := 0; i < n; i++ {
vals[i] = rand.NormFloat64()
}
p, err := plot.New()
if err != nil {
panic(err)
}
p.Title.Text = "Histogram"
h, err := plotter.NewHist(vals, 16)
if err != nil {
panic(err)
}
h.Normalize(1)
p.Add(h)
// The normal distribution function
norm := plotter.NewFunction(stdNorm)
norm.Color = color.RGBA{R: 255, A: 255}
norm.Width = vg.Points(2)
p.Add(norm)
return p
}