我試圖在C中實現Mandelbrot集,但我有一個奇怪的問題。我的代碼如下:我的Mandelbrot代碼有什麼問題?
#include <stdio.h>
#include <math.h>
#include <complex.h>
int iterate_pt(complex c);
int main() {
FILE *fp;
fp = fopen("mand.ppm", "w+");
double crmin = -.75;
double crmax = -.74;
double cimin = -.138;
double cimax = -.75; //Changing this value to -.127 fixed my problem.
int ncols = 256;
int nrows = 256;
int mand[ncols][nrows];
int x, y, color;
double complex c;
double dx = (crmax-crmin)/ncols;
double dy = (cimax-cimin)/nrows;
for (x = 0; x < ncols; x++){
for (y = 0; y < nrows; y++){
double complex imaginary = 0+1.0i;
c = crmin+(x*dx) + (cimin+(y*dy)) * imaginary;
mand[x][y] = iterate_pt(c);
}
}
printf("Printing ppm header.");
fprintf(fp, "P3\n");
fprintf(fp, "%d %d\n255\n\n", ncols, nrows);
for (x = 0; x < ncols; x++) {
for (y = 0; y < nrows; y++){
color = mand[x][y];
fprintf(fp, "%d\n", color);
fprintf(fp, "%d\n", color);
fprintf(fp, "%d\n\n", color); //Extra new line added, telling the ppm to go to next pixel.
}
}
fclose(fp);
return 0;
}
int iterate_pt(double complex c){
double complex z = 0+0.0i;
int iterations = 0;
int k;
for (k = 1; k <= 255; k++) {
z = z*z + c;
if (sqrt(z*conj(z)) > 50){
break;
}
else
++iterations;
}
return iterations;
}
然而,這一方案被存儲爲一個PPM文件的輸出看起來是這樣的:
感謝您的幫助!
檢查你的邏輯對這個僞代碼:http://en.wikipedia.org/wiki/Mandelbrot_set#For_programmers – Blender
我不知道這是否相關,但我得到'警告:未使用的變量'真正'當我編譯你的代碼。 –
我正在試驗不同的技術來表示真實和虛擬的數字,並忘記刪除它。 –