int main(void)
{
long idum=(-3);
unsigned long err,i,j,k,nn1=NX,nn2=NY,nn3=NZ;
float fnorm,***data1,***data2,**speq1;
fnorm=(float)nn1*(float)nn2*(float)nn3/2.0;
data1=f3tensor(1,nn1,1,nn2,1,nn3);
data2=f3tensor(1,nn1,1,nn2,1,nn3);
speq1=matrix(1,nn1,1,nn2<<1);
for (i=1;i<=nn1;i++)
for (j=1;j<=nn2;j++)
for (k=1;k<=nn3;k++)
data2[i][j][k]=fnorm*(data1[i][j][k]=2*ran1(&idum)-1);
rlft3(data1,speq1,nn1,nn2,nn3,1);
/* here would be any processing in Fourier space */
rlft3(data1,speq1,nn1,nn2,nn3,-1);
err=compare("data",data1,data2,nn1,nn2,nn3,EPS);
if (err) {
printf("Comparison error at tolerance %12.6f\n",EPS);
printf("Total number of errors is %d\n",err);
}
else {
printf("Data compares OK to tolerance %12.6f\n",EPS);
}
free_matrix(speq1,1,nn1,1,nn2<<1);
free_f3tensor(data2,1,nn1,1,nn2,1,nn3);
free_f3tensor(data1,1,nn1,1,nn2,1,nn3);
return (err > 0);
}
int main(void) /* example1 */
{
void rlft3(float ***data, float **speq, unsigned long nn1,
unsigned long nn2, unsigned long nn3, int isign);
float ***data, **speq;
data=f3tensor(1,1,1,N2,1,N3);
speq=matrix(1,1,1,2*N2);
rlft3(data,speq,1,N2,N3,1);
rlft3(data,speq,1,N2,N3,-1);
free_matrix(speq,1,1,1,2*N2);
free_f3tensor(data,1,1,1,N2,1,N3);
return 0;
}
int main(void) /* example3 */
{
void rlft3(float ***data, float **speq, unsigned long nn1,
unsigned long nn2, unsigned long nn3, int isign);
int j;
float fac,r,i,***data1,***data2,**speq1,**speq2,*sp1,*sp2;
data1=f3tensor(1,N,1,N,1,N);
data2=f3tensor(1,N,1,N,1,N);
speq1=matrix(1,N,1,2*N);
speq2=matrix(1,N,1,2*N);
rlft3(data1,speq1,N,N,N,1);
rlft3(data2,speq2,N,N,N,1);
fac=2.0/(N*N*N);
sp1 = &data1[1][1][1];
sp2 = &data2[1][1][1];
for (j=1;j<=N*N*N/2;j++) {
r = sp1[0]*sp2[0] - sp1[1]*sp2[1];
i = sp1[0]*sp2[1] + sp1[1]*sp2[0];
sp1[0] = fac*r;
sp1[1] = fac*i;
sp1 += 2;
sp2 += 2;
}
sp1 = &speq1[1][1];
sp2 = &speq2[1][1];
for (j=1;j<=N*N;j++) {
r = sp1[0]*sp2[0] - sp1[1]*sp2[1];
i = sp1[0]*sp2[1] + sp1[1]*sp2[0];
sp1[0] = fac*r;
sp1[1] = fac*i;
sp1 += 2;
sp2 += 2;
}
rlft3(data1,speq1,N,N,N,-1);
free_matrix(speq2,1,N,1,2*N);
free_matrix(speq1,1,N,1,2*N);
free_f3tensor(data2,1,N,1,N,1,N);
free_f3tensor(data1,1,N,1,N,1,N);
return 0;
}
