void cow_fft_reverse(cow_dfield *f, cow_dfield *fkre, cow_dfield *fkim)
{
int nx = cow_domain_getnumlocalzonesinterior(f->domain, 0);
int ny = cow_domain_getnumlocalzonesinterior(f->domain, 1);
int nz = cow_domain_getnumlocalzonesinterior(f->domain, 2);
int ng = cow_domain_getguard(f->domain);
int ntot = nx * ny * nz;
int I0[3] = { ng, ng, ng };
int I1[3] = { nx + ng, ny + ng, nz + ng };
double *out = (double*) malloc(ntot * sizeof(double) * f->n_members);
double *inr = (double*) malloc(ntot * sizeof(double) * f->n_members);
double *ini = (double*) malloc(ntot * sizeof(double) * f->n_members);
cow_dfield_extract(fkre, I0, I1, inr);
cow_dfield_extract(fkim, I0, I1, ini);
for (int m=0; m<f->n_members; ++m) {
FFT_DATA *fk = (FFT_DATA*) malloc(ntot * sizeof(FFT_DATA));
for (int n=0; n<ntot; ++n) {
fk[n][0] = inr[f->n_members*n + m];
fk[n][1] = ini[f->n_members*n + m];
}
double *fx = _rev(f->domain, fk);
for (int n=0; n<ntot; ++n) {
out[f->n_members*n + m] = fx[n];
}
free(fx);
free(fk);
}
cow_dfield_replace(f, I0, I1, out);
free(out);
free(inr);
free(ini);
}
Node* _rev(Node *head) {
if(head->next == NULL) {
newHead = head;
return newHead;
} else {
_rev(head->next)->next = head;
head->next = NULL;
return head;
}
}
void _rev(const char * str, int len, int p, char * rv)
{
if (p == len - 1) {
rv[0] = str[p];
return;
}
rv[len - 1 - p] = str[p];
_rev(str, len, p + 1, rv);
}
void cow_fft_helmholtzdecomp(cow_dfield *f, int mode)
{
#if (COW_FFTW)
if (!f->committed) return;
if (f->n_members != 3) {
printf("[%s] error: need a 3-component field for pspecvectorfield", MODULE);
return;
}
clock_t start = clock();
int nx = cow_domain_getnumlocalzonesinterior(f->domain, 0);
int ny = cow_domain_getnumlocalzonesinterior(f->domain, 1);
int nz = cow_domain_getnumlocalzonesinterior(f->domain, 2);
int ng = cow_domain_getguard(f->domain);
int ntot = nx * ny * nz;
int I0[3] = { ng, ng, ng };
int I1[3] = { nx + ng, ny + ng, nz + ng };
double *input = (double*) malloc(3 * ntot * sizeof(double));
cow_dfield_extract(f, I0, I1, input);
FFT_DATA *gx = _fwd(f->domain, input, 0, 3); // start, stride
FFT_DATA *gy = _fwd(f->domain, input, 1, 3);
FFT_DATA *gz = _fwd(f->domain, input, 2, 3);
free(input);
FFT_DATA *gx_p = (FFT_DATA*) malloc(ntot * sizeof(FFT_DATA));
FFT_DATA *gy_p = (FFT_DATA*) malloc(ntot * sizeof(FFT_DATA));
FFT_DATA *gz_p = (FFT_DATA*) malloc(ntot * sizeof(FFT_DATA));
for (int i=0; i<nx; ++i) {
for (int j=0; j<ny; ++j) {
for (int k=0; k<nz; ++k) {
int m = i*ny*nz + j*nz + k;
FFT_DATA gdotk;
double khat[3];
khat_at(f->domain, i, j, k, khat);
gdotk[0] = gx[m][0] * khat[0] + gy[m][0] * khat[1] + gz[m][0] * khat[2];
gdotk[1] = gx[m][1] * khat[0] + gy[m][1] * khat[1] + gz[m][1] * khat[2];
switch (mode) {
case COW_PROJECT_OUT_DIV:
gx_p[m][0] = gx[m][0] - gdotk[0] * khat[0];
gx_p[m][1] = gx[m][1] - gdotk[1] * khat[0];
gy_p[m][0] = gy[m][0] - gdotk[0] * khat[1];
gy_p[m][1] = gy[m][1] - gdotk[1] * khat[1];
gz_p[m][0] = gz[m][0] - gdotk[0] * khat[2];
gz_p[m][1] = gz[m][1] - gdotk[1] * khat[2];
break;
case COW_PROJECT_OUT_CURL:
gx_p[m][0] = gdotk[0] * khat[0];
gx_p[m][1] = gdotk[1] * khat[0];
gy_p[m][0] = gdotk[0] * khat[1];
gy_p[m][1] = gdotk[1] * khat[1];
gz_p[m][0] = gdotk[0] * khat[2];
gz_p[m][1] = gdotk[1] * khat[2];
break;
default: break;
}
}
}
}
free(gx);
free(gy);
free(gz);
double *fx_p = _rev(f->domain, gx_p);
double *fy_p = _rev(f->domain, gy_p);
double *fz_p = _rev(f->domain, gz_p);
free(gx_p);
free(gy_p);
free(gz_p);
double *res = (double*) malloc(3 * ntot * sizeof(double));
for (int i=0; i<ntot; ++i) {
res[3*i + 0] = fx_p[i];
res[3*i + 1] = fy_p[i];
res[3*i + 2] = fz_p[i];
}
free(fx_p);
free(fy_p);
free(fz_p);
cow_dfield_replace(f, I0, I1, res);
cow_dfield_syncguard(f);
free(res);
printf("[%s] %s took %3.2f seconds\n",
MODULE, __FUNCTION__, (double) (clock() - start) / CLOCKS_PER_SEC);
#endif // COW_FFTW
}
Node* Reverse(Node *head)
{
_rev(head);
return newHead;
}
