gonum scatter plot

main.go

package main

import (
	"image/color"
	"math/rand"

	"github.com/gonum/plot"
	"github.com/gonum/plot/plotter"
	"github.com/gonum/plot/vg"
)

func main() {
	// Get some random points
	rand.Seed(int64(0))
	n := 15
	scatterData := randomPoints(n)

	// Create a new plot, set its title and
	// axis labels.
	p, err := plot.New()
	if err != nil {
		panic(err)
	}
	p.Title.Text = "Points Example"
	p.X.Label.Text = "X"
	p.Y.Label.Text = "Y"
	// Draw a grid behind the data
	p.Add(plotter.NewGrid())

	// Make a scatter plotter and set its style.
	s, err := plotter.NewScatter(scatterData)
	if err != nil {
		panic(err)
	}
	s.GlyphStyle.Color = color.RGBA{R: 255, B: 128, A: 255}
	p.Add(s)

	// Save the plot to a PNG file.
	if err := p.Save(4*vg.Inch, 4*vg.Inch, "scatter.png"); err != nil {
		panic(err)
	}
}

// randomPoints returns some random x, y points.
func randomPoints(n int) plotter.XYs {
	pts := make(plotter.XYs, n)
	for i := range pts {
		if i == 0 {
			pts[i].X = rand.Float64()
		} else {
			pts[i].X = pts[i-1].X + rand.Float64()
		}
		pts[i].Y = pts[i].X + 10*rand.Float64()
	}
	return pts
}