/**
* construct makes an 2d-nfft for every slice
*/
static void construct(char * file, int N, int M, int Z, fftw_complex *mem)
{
int j,z; /* some variables */
double tmp; /* a placeholder */
nfft_plan my_plan; /* plan for the two dimensional nfft */
FILE* fp;
/* initialise my_plan */
nfft_init_2d(&my_plan,N,N,M/Z);
fp=fopen("knots.dat","r");
for(j=0;j<my_plan.M_total;j++)
{
fscanf(fp,"%le %le %le",&my_plan.x[2*j+0],&my_plan.x[2*j+1],&tmp);
}
fclose(fp);
fp=fopen(file,"w");
for(z=0;z<Z;z++) {
tmp = (double) z;
for(j=0;j<N*N;j++)
my_plan.f_hat[j] = mem[(z*N*N+N*N*Z/2+j)%(N*N*Z)];
if(my_plan.flags & PRE_PSI)
nfft_precompute_psi(&my_plan);
nfft_trafo(&my_plan);
for(j=0;j<my_plan.M_total;j++)
{
fprintf(fp,"%le %le %le %le %le\n",my_plan.x[2*j+0],my_plan.x[2*j+1],tmp/Z-0.5,
creal(my_plan.f[j]),cimag(my_plan.f[j]));
}
}
fclose(fp);
nfft_finalize(&my_plan);
}
void // space to frequency
mad_cmat_nfft (const cnum_t x[], const num_t x_node[], cnum_t r[], ssz_t m, ssz_t n, ssz_t nr)
{
assert( x && r );
int precomp = 0;
if (m != p_n1 || n != p_n2 || nr != p_m) {
nfft_finalize(&p);
nfft_init_2d (&p, m, n, nr);
p_n1 = m, p_n2 = n, p_m = nr, precomp = 1;
}
if (x_node || precomp) {
for (ssz_t i=0; i < m*n; i++) // adjoint transform needs -x_node
p.x[i] = x_node[i] == -0.5 ? 0.4999999999999999 : -x_node[i];
if(p.flags & PRE_ONE_PSI) nfft_precompute_one_psi(&p);
}
mad_cvec_copy(x, p.f, m*n);
const char *error_str = nfft_check(&p);
if (error_str) error("%s", error_str);
nfft_adjoint(&p); // nfft_adjoint_direct(&p);
// mad_cvec_copy(p.f_hat, r, nr);
mad_cvec_copy(p.f_hat+nr/2, r, nr/2); // for compatibility with FFTW ?? (TBC)
mad_cvec_copy(p.f_hat, r+nr/2, nr/2);
}
void // frequency to space
mad_cmat_infft (const cnum_t x[], const num_t r_node[], cnum_t r[], ssz_t m, ssz_t n, ssz_t nx)
{
assert( x && r );
int precomp = 0;
if (m != p_n1 || n != p_n2 || nx != p_m) {
nfft_finalize(&p);
nfft_init_2d (&p, m, n, nx);
p_n1 = m, p_n2 = n, p_m = nx, precomp = 1;
}
if (r_node || precomp) {
for (ssz_t i=0; i < m*n; i++) // forward transform needs -r_node
p.x[i] = r_node[i] == -0.5 ? 0.4999999999999999 : -r_node[i];
if(p.flags & PRE_ONE_PSI) nfft_precompute_one_psi(&p);
}
// mad_cvec_copy(x, p.f_hat, nx);
mad_cvec_copy(x+nx/2, p.f_hat, nx/2); // for compatibility with FFTW ?? (TBC)
mad_cvec_copy(x, p.f_hat+nx/2, nx/2);
const char *error_str = nfft_check(&p);
if (error_str) error("%s", error_str);
nfft_trafo(&p); // nfft_trafo_direct(&p);
mad_cvec_copy(p.f, r, m*n);
mad_cvec_muln(r, 1.0/(m*n), r, m*n);
}
void FC_FUNC(oct_nfft_init_2d,OCT_NFFT_INIT_2D)
(nfft_plan *plan, int *N1, int *N2, int *M)
{
nfft_init_2d(plan, *N1, *N2, *M);
}
