Hi, I have made a program ( main code below , not all, ) It works good, but not terminates ( I must use Ctrl-Z to stop it ) I do not know the reason of it. Thx in advanace Adam -----Console ------------------- adam@adam-laptop:~/c/interior/ilsmj/d/v/v1$ gcc a.c -lm -Wall adam@adam-laptop:~/c/interior/ilsmj/d/v/v1$ ./a.out memory is OK File a0.100000000.pgm saved. File a0.105000000.pgm saved. File a0.110000000.pgm saved. File a0.115000000.pgm saved. File a0.120000000.pgm saved. File a0.125000000.pgm saved. File a0.130000000.pgm saved. File a0.135000000.pgm saved. File a0.140000000.pgm saved. File a0.145000000.pgm saved. File a0.150000000.pgm saved. File a0.155000000.pgm saved. File a0.160000000.pgm saved. File a0.165000000.pgm saved. File a0.170000000.pgm saved. File a0.175000000.pgm saved. File a0.180000000.pgm saved. File a0.185000000.pgm saved. File a0.190000000.pgm saved. done ---------- code --------------- int main() { double complex Za; /* atractor ZA = ZAx + ZAy*i */ /* */ double aR; double aRmax=0.2; double aRmin= 0.1; int i,iMax=20; double step_aR = (aRmax-aRmin)/20; /* dynamic 1D arrays for colors ( shades of gray ) */ unsigned char *Data, *Edge; Data = malloc( iLength * sizeof(unsigned char) ); Edge = malloc( iLength * sizeof(unsigned char) ); if (Data == NULL || Edge==NULL) { fprintf(stderr,"Could not allocate memory"); getchar(); return 1; } else { printf("memory is OK\n"); Za = GiveAttractor( Cx, Cy, ER2, IterationMaxBig); for(i=0;i<iMax-1;i++){ aR = aRmin+i*step_aR; Make_File( aR, Data, Edge, Za); } /* --------------free memory ---------------------*/ free(Data); free(Edge); printf("done \n"); return 0; } }