mri2d/reconstruct_data_gridding.c
/*
* Copyright (c) 2002, 2017 Jens Keiner, Stefan Kunis, Daniel Potts
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option) any later
* version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include <stdlib.h>
#include <math.h>
#ifdef HAVE_COMPLEX_H
#include <complex.h>
#endif
#include "nfft3.h"
static void reconstruct(char* filename, int N, int M, int weight)
{
int j; /* some variables */
double weights; /* store one weight temporary */
double real,imag; /* to read the real and imag part of a complex number */
nfft_plan my_plan; /* plan for the two dimensional nfft */
FILE* fin; /* input file */
FILE* fweight; /* input file for the weights */
FILE *fout_real; /* output file */
FILE *fout_imag; /* output file */
int my_N[2],my_n[2];
int flags = PRE_PHI_HUT| PRE_PSI |MALLOC_X| MALLOC_F_HAT|
MALLOC_F| FFTW_INIT| FFT_OUT_OF_PLACE|
FFTW_MEASURE| FFTW_DESTROY_INPUT;
/* initialise nfft */
my_N[0]=N; my_n[0]=ceil(N*1.2);
my_N[1]=N; my_n[1]=ceil(N*1.2);
nfft_init_guru(&my_plan, 2, my_N, M, my_n, 6,flags,
FFTW_MEASURE| FFTW_DESTROY_INPUT);
fin=fopen(filename,"r");
fweight=fopen("weights.dat","r");
for(j=0;j<my_plan.M_total;j++)
{
fscanf(fweight,"%le ",&weights);
fscanf(fin,"%le %le %le %le",&my_plan.x[2*j+0],&my_plan.x[2*j+1],&real,&imag);
my_plan.f[j] = real + _Complex_I*imag;
if (weight)
my_plan.f[j] = my_plan.f[j] * weights;
}
fclose(fweight);
/* precompute psi */
if(my_plan.flags & PRE_PSI)
nfft_precompute_psi(&my_plan);
/* precompute full psi */
if(my_plan.flags & PRE_FULL_PSI)
nfft_precompute_full_psi(&my_plan);
/* compute the adjoint nfft */
nfft_adjoint(&my_plan);
fout_real=fopen("output_real.dat","w");
fout_imag=fopen("output_imag.dat","w");
for (j=0;j<N*N;j++) {
fprintf(fout_real,"%le ",creal(my_plan.f_hat[j]));
fprintf(fout_imag,"%le ",cimag(my_plan.f_hat[j]));
}
fclose(fin);
fclose(fout_real);
fclose(fout_imag);
nfft_finalize(&my_plan);
}
int main(int argc, char **argv)
{
if (argc <= 5) {
printf("usage: ./reconstruct_data_gridding FILENAME N M ITER WEIGHTS\n");
return 1;
}
reconstruct(argv[1],atoi(argv[2]),atoi(argv[3]),atoi(argv[5]));
return 1;
}
/* \} */
nfft_plan::f_hat
fftw_complex * f_hat
Fourier coefficients.
Definition: nfft3.h:192
MALLOC_X
#define MALLOC_X
Definition: nfft3.h:199
MALLOC_F_HAT
#define MALLOC_F_HAT
Definition: nfft3.h:200
nfft_precompute_full_psi
void nfft_precompute_full_psi(nfft_plan *ths)
nfft_adjoint
void nfft_adjoint(nfft_plan *ths)
nfft_plan::f
fftw_complex * f
Samples.
Definition: nfft3.h:192
nfft_precompute_psi
void nfft_precompute_psi(nfft_plan *ths)
nfft_plan
data structure for an NFFT (nonequispaced fast Fourier transform) plan with double precision ...
Definition: nfft3.h:192
FFTW_INIT
#define FFTW_INIT
Definition: nfft3.h:203
MALLOC_F
#define MALLOC_F
Definition: nfft3.h:201
nfft_plan::M_total
NFFT_INT M_total
Total number of samples.
Definition: nfft3.h:192
FFT_OUT_OF_PLACE
#define FFT_OUT_OF_PLACE
Definition: nfft3.h:202
PRE_PSI
#define PRE_PSI
Definition: nfft3.h:197
nfft_finalize
void nfft_finalize(nfft_plan *ths)
reconstruct
static void reconstruct(char *filename, int N, int M, int weight)
reconstruct makes a 2d-adjoint-nfft
Definition: mri2d/reconstruct_data_gridding.c:37
PRE_FULL_PSI
#define PRE_FULL_PSI
Definition: nfft3.h:198
nfft3.h
Header file for the nfft3 library.
nfft_plan::x
double * x
Nodes in time/spatial domain, size is doubles.
Definition: nfft3.h:192
PRE_PHI_HUT
#define PRE_PHI_HUT
Definition: nfft3.h:193
nfft_plan::flags
unsigned flags
Flags for precomputation, (de)allocation, and FFTW usage, default setting is PRE_PHI_HUT | PRE_PSI | ...
Definition: nfft3.h:192