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package main
import (
"math/rand"
"github.com/fogleman/gg"
)
func CreatePoints(n int) []gg.Point {
points := make([]gg.Point, n)
for i := 0; i < n; i++ {
x := 0.5 + rand.NormFloat64()*0.1
y := x + rand.NormFloat64()*0.1
points[i] = gg.Point{x, y}
}
return points
}
func main() {
const S = 1024
const P = 64
dc := gg.NewContext(S, S)
dc.InvertY()
dc.SetRGB(1, 1, 1)
dc.Clear()
points := CreatePoints(1000)
dc.Translate(P, P)
dc.Scale(S-P*2, S-P*2)
// draw minor grid
for i := 1; i <= 10; i++ {
x := float64(i) / 10
dc.MoveTo(x, 0)
dc.LineTo(x, 1)
dc.MoveTo(0, x)
dc.LineTo(1, x)
}
dc.SetRGBA(0, 0, 0, 0.25)
dc.SetLineWidth(1)
dc.Stroke()
// draw axes
dc.MoveTo(0, 0)
dc.LineTo(1, 0)
dc.MoveTo(0, 0)
dc.LineTo(0, 1)
dc.SetRGB(0, 0, 0)
dc.SetLineWidth(4)
dc.Stroke()
// draw points
dc.SetRGBA(0, 0, 1, 0.5)
for _, p := range points {
dc.DrawCircle(p.X, p.Y, 3.0/S)
dc.Fill()
}
// draw text
dc.Identity()
dc.SetRGB(0, 0, 0)
if err := dc.LoadFontFace("/Library/Fonts/Arial Bold.ttf", 24); err != nil {
panic(err)
}
dc.DrawStringAnchored("Chart Title", S/2, P/2, 0.5, 0.5)
if err := dc.LoadFontFace("/Library/Fonts/Arial.ttf", 18); err != nil {
panic(err)
}
dc.DrawStringAnchored("X Axis Title", S/2, S-P/2, 0.5, 0.5)
dc.SavePNG("out.png")
}
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