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