main()
{
int n1,n2,j;
float scale,sumz,sume;
for (n1=1,n2=npfa(n1+1); n2<NMAX; n1=n2,n2=npfa(n1+1)) {
for (j=0; j<n1*n2; j++)
c[j] = z[j] = cmplx(franuni(),franuni());
pfamcc(1,n1,n2,1,n1,z);
pfamcc(1,n2,n1,n1,1,z);
pfamcc(-1,n1,n2,1,n1,z);
pfamcc(-1,n2,n1,n1,1,z);
scale = 1.0/(float)(n1*n2);
for (j=0; j<n1*n2; j++)
z[j] = crmul(z[j],scale);
for (j=0,sumz=sume=0.0; j<n1*n2; j++) {
sumz += fcabs(z[j]);
sume += fcabs(csub(z[j],c[j]));
}
printf("n1 = %d n2 = %d sume/sumz = %0.10f\n",
n1,n2,sume/sumz);
if (sume/sumz>1.0e-6) printf("!!! warning !!!\n");
}
}
void ccm_fft(complex *cdata, int n1, int n2, int ld1, int sign)
{
int i, j;
double *real, *imag;
if (NINT(pow(2.0, (double)NINT(log((double)n1)/log(2.0)))) != n1) {
if (npfa(n1) == n1) pfamcc(sign, n1, n2, 1, ld1, cdata);
else {
for (i = 0; i < n2; i++) ccdft(&cdata[i*ld1],n1,sign);
}
}
else {
real = (double *)malloc(n1*sizeof(double));
if (real == NULL) fprintf(stderr,"ccm_fft: memory allocation error\n");
imag = (double *)malloc(n1*sizeof(double));
if (imag == NULL) fprintf(stderr,"ccm_fft: memory allocation error\n");
for (i = 0; i < n2; i++) {
for (j = 0; j < n1; j++) {
real[j] = (double)cdata[i*ld1+j].r;
imag[j] = (double)cdata[i*ld1+j].i;
}
if (sign < 0) fft(n1, real, imag);
else ifft(n1, real, imag);
for (j = 0; j < n1; j++) {
cdata[i*ld1+j].r = (REAL)real[j];
cdata[i*ld1+j].i = (REAL)imag[j];
}
}
free(real);
free(imag);
}
return;
}
