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// Copyright ©2015 The Gonum Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package plotter_test
import (
"image/color"
"log"
"math"
"gonum.org/v1/plot"
"gonum.org/v1/plot/plotter"
"gonum.org/v1/plot/vg"
)
// ExampleFunction draws some functions.
func ExampleFunction() {
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, err := plot.New()
if err != nil {
log.Panic(err)
}
p.Title.Text = "Functions"
p.X.Label.Text = "X"
p.Y.Label.Text = "Y"
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 = 0.5 * vg.Inch
p.X.Min = 0
p.X.Max = 10
p.Y.Min = 0
p.Y.Max = 100
err = p.Save(200, 200, "testdata/functions.png")
if err != nil {
log.Panic(err)
}
}
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