/*********************************************** * Newtz4C.c * * Generates a RAW format file of an image * of a Julia set attractor of Newton's method (grayscale) * * C source file by Alberto Strumia * ************************************************/ #include /* definition of constants */ #define Radius 0.99 #define Cx 0 #define Cy 0 #define Side 0.1 #define M 700 #define Num 64 /* main program */ main() { int p, q, n, w; double x, y, xx, yy, Incx, Incy; FILE *fp; fp = fopen("Newt.raw","w"); for (p = 1; p <= M; p++) { Incy = - Side + 2*Side/M*p; printf("%i %%\n", p*100/M); for (q = 1; q <= M; q++) { Incx = - Side + 2*Side/M*q; x = Incx; y = Incy; w = 0; for ( n = 1; n <= Num; ++n) { xx = 3*x/4 - x*(x*x - 3*y*y)/(x*x + y*y)/(x*x + y*y)/(x*x + y*y)/4; yy = 3*y/4 - y*(y*y - 3*x*x)/(x*x + y*y)/(x*x + y*y)/(x*x + y*y)/4; x = xx; y = yy; if ( (x-Cx)*(x-Cx) + (y-Cy)*(y-Cy) < Radius ) { w = n; } } fprintf(fp, "%c", 255*w*w/Num/Num ); } } fclose(fp); } /* end of main program */