mri3d/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 Z, int weight ,fftw_complex *mem)
{
int j,k,z; /* some variables */
double weights; /* store one weight temporary */
double tmp; /* tmp to read the obsolent z from the input file */
double real,imag; /* to read the real and imag part of a complex number */
nfft_plan my_plan; /* plan for the two dimensional nfft */
int my_N[2],my_n[2]; /* to init the nfft */
FILE* fin; /* input file */
FILE* fweight; /* input file for the weights */
/* initialise my_plan */
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/Z, my_n, 6, PRE_PHI_HUT| PRE_PSI|
MALLOC_X| MALLOC_F_HAT| MALLOC_F|
FFTW_INIT| FFT_OUT_OF_PLACE,
FFTW_MEASURE| FFTW_DESTROY_INPUT);
/* precompute lin psi if set */
if(my_plan.flags & PRE_LIN_PSI)
nfft_precompute_lin_psi(&my_plan);
fin=fopen(filename,"r");
for(z=0;z<Z;z++) {
fweight=fopen("weights.dat","r");
for(j=0;j<my_plan.M_total;j++)
{
fscanf(fweight,"%le ",&weights);
fscanf(fin,"%le %le %le %le %le",
&my_plan.x[2*j+0],&my_plan.x[2*j+1],&tmp,&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 set just one time because the knots equal each slice */
if(z==0 && my_plan.flags & PRE_PSI)
nfft_precompute_psi(&my_plan);
/* precompute full psi if set just one time because the knots equal each slice */
if(z==0 && my_plan.flags & PRE_FULL_PSI)
nfft_precompute_full_psi(&my_plan);
/* compute the adjoint nfft */
nfft_adjoint(&my_plan);
for(k=0;k<my_plan.N_total;k++) {
/* write every slice in the memory.
here we make an fftshift direct */
mem[(Z*N*N/2+z*N*N+ k)%(Z*N*N)] = my_plan.f_hat[k];
}
}
fclose(fin);
nfft_finalize(&my_plan);
}
static void print(int N,int M,int Z, fftw_complex *mem)
{
int i,j;
FILE* fout_real;
FILE* fout_imag;
fout_real=fopen("output_real.dat","w");
fout_imag=fopen("output_imag.dat","w");
for(i=0;i<Z;i++) {
for (j=0;j<N*N;j++) {
fprintf(fout_real,"%le ",creal(mem[(Z*N*N/2+i*N*N+ j)%(Z*N*N)]) /Z);
fprintf(fout_imag,"%le ",cimag(mem[(Z*N*N/2+i*N*N+ j)%(Z*N*N)]) /Z);
}
fprintf(fout_real,"\n");
fprintf(fout_imag,"\n");
}
fclose(fout_real);
fclose(fout_imag);
}
int main(int argc, char **argv)
{
fftw_complex *mem;
fftw_plan plan;
int N,M,Z;
if (argc <= 6) {
printf("usage: ./reconstruct_data_gridding FILENAME N M Z ITER WEIGHTS\n");
return 1;
}
N=atoi(argv[2]);
M=atoi(argv[3]);
Z=atoi(argv[4]);
/* Allocate memory to hold every slice in memory after the
2D-infft */
mem = (fftw_complex*) nfft_malloc(sizeof(fftw_complex) * atoi(argv[2]) * atoi(argv[2]) * atoi(argv[4]));
/* Create plan for the 1d-ifft */
plan = fftw_plan_many_dft(1, &Z, N*N,
mem, NULL,
N*N, 1,
mem, NULL,
N*N,1 ,
FFTW_BACKWARD, FFTW_MEASURE);
/* execute the 2d-nfft's */
reconstruct(argv[1],atoi(argv[2]),atoi(argv[3]),atoi(argv[4]),atoi(argv[6]),mem);
/* execute the 1d-fft's */
fftw_execute(plan);
/* write the memory back in files */
print(N,M,Z, mem);
/* free memory */
nfft_free(mem);
return 1;
}
/* \} */
print
static void print(int N, int M, int Z, fftw_complex *mem)
print writes the memory back in a file output_real.dat for the real part and output_imag.dat for the imaginary part
Definition: mri3d/reconstruct_data_gridding.c:101
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_lin_psi
void nfft_precompute_lin_psi(nfft_plan *ths)
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
reconstruct
static void reconstruct(char *filename, int N, int M, int Z, int weight, fftw_complex *mem)
reconstruct makes an 2d-adjoint-nfft for every slice
Definition: mri3d/reconstruct_data_gridding.c:37
nfft_free
void nfft_free(void *p)
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
nfft_plan::N_total
NFFT_INT N_total
Total number of Fourier coefficients.
Definition: nfft3.h:192
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_LIN_PSI
#define PRE_LIN_PSI
Definition: nfft3.h:195
PRE_PSI
#define PRE_PSI
Definition: nfft3.h:197
nfft_malloc
void * nfft_malloc(size_t n)
nfft_finalize
void nfft_finalize(nfft_plan *ths)
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