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January 2, 2016 08:39
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Goでフラクタルを書いてみました。
各点がFatou集合に入ってるかどうかを並列に計算する単純なものです。
結果は同じフォルダに"result.png"として出力されます。
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package main | |
import ( | |
"fmt" | |
"math/cmplx" | |
"image" | |
"image/png" | |
"os" | |
) | |
// 生成する画像の大きさと解像度 | |
const width = 800 | |
const height = 800 | |
const scale = 200 | |
const infty = 1000000.0 | |
const max_iterate = 50 | |
func f(z complex128) complex128 { | |
return z*z + complex(-0.765,0.12) | |
} | |
func inFatou(z complex128) bool{ | |
for i:=0;i<max_iterate;i++ { | |
z = f(z) | |
if cmplx.Abs(z)>infty { return true } | |
} | |
return false | |
} | |
func main(){ | |
points := width * height | |
// 画像の生成と初期化 | |
fmt.Println("Calclating Julia Set") | |
img := image.NewGray(image.Rect(0,0,width,height)) | |
c := make(chan int, points) | |
for x:=0;x<width;x+=1 { | |
for y:=0;y<height;y+=1 { | |
go func(x,y int, c chan int){ | |
z := pixelToComplex(x,y) | |
if inFatou(z) { | |
img.Pix[y*width + x] = 255 | |
}else{ | |
img.Pix[y*width + x] = 0 | |
} | |
c <- 1 | |
}(x,y,c) | |
} | |
} | |
for i := 0; i<points; i++ { | |
<-c | |
} | |
// 画像出力 | |
fmt.Println("Making Result...") | |
file, err := os.Create("result.png") | |
if err != nil { | |
panic(err) | |
} | |
defer file.Close() | |
png.Encode(file, img) | |
if err != nil { | |
panic(err) | |
} | |
} | |
func pixelToComplex(x,y int) complex128 { | |
return complex(float64(x-width/2)/float64(scale),float64(y-height/2)/float64(scale)) | |
} |
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