NFFT 3.5.3alpha
mri2d/reconstruct_data_gridding.c
1/*
2 * Copyright (c) 2002, 2017 Jens Keiner, Stefan Kunis, Daniel Potts
3 *
4 * This program is free software; you can redistribute it and/or modify it under
5 * the terms of the GNU General Public License as published by the Free Software
6 * Foundation; either version 2 of the License, or (at your option) any later
7 * version.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
11 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
12 * details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 */
18#include "config.h"
19
20#include <stdlib.h>
21#include <math.h>
22#ifdef HAVE_COMPLEX_H
23#include <complex.h>
24#endif
25
26#include "nfft3.h"
27
37static void reconstruct(char* filename, int N, int M, int weight)
38{
39 int j; /* some variables */
40 double weights; /* store one weight temporary */
41 double real,imag; /* to read the real and imag part of a complex number */
42 nfft_plan my_plan; /* plan for the two dimensional nfft */
43 FILE* fin; /* input file */
44 FILE* fweight; /* input file for the weights */
45 FILE *fout_real; /* output file */
46 FILE *fout_imag; /* output file */
47 int my_N[2],my_n[2];
49 MALLOC_F| FFTW_INIT| FFTW_MEASURE;
50
51 /* initialise nfft */
52 my_N[0]=N; my_n[0]=ceil(N*1.2);
53 my_N[1]=N; my_n[1]=ceil(N*1.2);
54 nfft_init_guru(&my_plan, 2, my_N, M, my_n, 6,flags,
55 FFTW_MEASURE| FFTW_DESTROY_INPUT);
56
57 fin=fopen(filename,"r");
58
59 fweight=fopen("weights.dat","r");
60 for(j=0;j<my_plan.M_total;j++)
61 {
62 fscanf(fweight,"%le ",&weights);
63 fscanf(fin,"%le %le %le %le",&my_plan.x[2*j+0],&my_plan.x[2*j+1],&real,&imag);
64 my_plan.f[j] = real + _Complex_I*imag;
65 if (weight)
66 my_plan.f[j] = my_plan.f[j] * weights;
67 }
68 fclose(fweight);
69
70 /* precompute psi */
71 if(my_plan.flags & PRE_PSI)
72 nfft_precompute_psi(&my_plan);
73
74 /* precompute full psi */
75 if(my_plan.flags & PRE_FULL_PSI)
76 nfft_precompute_full_psi(&my_plan);
77
78
79 /* compute the adjoint nfft */
80 nfft_adjoint(&my_plan);
81
82 fout_real=fopen("output_real.dat","w");
83 fout_imag=fopen("output_imag.dat","w");
84
85 for (j=0;j<N*N;j++) {
86 fprintf(fout_real,"%le ",creal(my_plan.f_hat[j]));
87 fprintf(fout_imag,"%le ",cimag(my_plan.f_hat[j]));
88 }
89
90 fclose(fin);
91 fclose(fout_real);
92 fclose(fout_imag);
93
94 nfft_finalize(&my_plan);
95}
96
97
98int main(int argc, char **argv)
99{
100 if (argc <= 5) {
101 printf("usage: ./reconstruct_data_gridding FILENAME N M ITER WEIGHTS\n");
102 return 1;
103 }
104 reconstruct(argv[1],atoi(argv[2]),atoi(argv[3]),atoi(argv[5]));
105
106 return 1;
107}
108/* \} */
static void reconstruct(char *filename, int N, int M, int weight)
reconstruct makes a 2d-adjoint-nfft
#define MALLOC_F_HAT
Definition nfft3.h:194
#define MALLOC_X
Definition nfft3.h:193
#define PRE_FULL_PSI
Definition nfft3.h:192
#define PRE_PSI
Definition nfft3.h:191
#define MALLOC_F
Definition nfft3.h:195
#define FFTW_INIT
Definition nfft3.h:197
#define PRE_PHI_HUT
Definition nfft3.h:187
Header file for the nfft3 library.