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NFFT
3.3.2
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00001 /* 00002 * Copyright (c) 2002, 2016 Jens Keiner, Stefan Kunis, Daniel Potts 00003 * 00004 * This program is free software; you can redistribute it and/or modify it under 00005 * the terms of the GNU General Public License as published by the Free Software 00006 * Foundation; either version 2 of the License, or (at your option) any later 00007 * version. 00008 * 00009 * This program is distributed in the hope that it will be useful, but WITHOUT 00010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 00011 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 00012 * details. 00013 * 00014 * You should have received a copy of the GNU General Public License along with 00015 * this program; if not, write to the Free Software Foundation, Inc., 51 00016 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 00017 */ 00018 #include "config.h" 00019 00020 #include <stdlib.h> 00021 #include <math.h> 00022 #ifdef HAVE_COMPLEX_H 00023 #include <complex.h> 00024 #endif 00025 00026 #include "nfft3.h" 00027 00037 static void reconstruct(char* filename, int N, int M, int weight) 00038 { 00039 int j; /* some variables */ 00040 double weights; /* store one weight temporary */ 00041 double real,imag; /* to read the real and imag part of a complex number */ 00042 nfft_plan my_plan; /* plan for the two dimensional nfft */ 00043 FILE* fin; /* input file */ 00044 FILE* fweight; /* input file for the weights */ 00045 FILE *fout_real; /* output file */ 00046 FILE *fout_imag; /* output file */ 00047 int my_N[2],my_n[2]; 00048 int flags = PRE_PHI_HUT| PRE_PSI |MALLOC_X| MALLOC_F_HAT| 00049 MALLOC_F| FFTW_INIT| FFT_OUT_OF_PLACE| 00050 FFTW_MEASURE| FFTW_DESTROY_INPUT; 00051 00052 /* initialise nfft */ 00053 my_N[0]=N; my_n[0]=ceil(N*1.2); 00054 my_N[1]=N; my_n[1]=ceil(N*1.2); 00055 nfft_init_guru(&my_plan, 2, my_N, M, my_n, 6,flags, 00056 FFTW_MEASURE| FFTW_DESTROY_INPUT); 00057 00058 fin=fopen(filename,"r"); 00059 00060 fweight=fopen("weights.dat","r"); 00061 for(j=0;j<my_plan.M_total;j++) 00062 { 00063 fscanf(fweight,"%le ",&weights); 00064 fscanf(fin,"%le %le %le %le",&my_plan.x[2*j+0],&my_plan.x[2*j+1],&real,&imag); 00065 my_plan.f[j] = real + _Complex_I*imag; 00066 if (weight) 00067 my_plan.f[j] = my_plan.f[j] * weights; 00068 } 00069 fclose(fweight); 00070 00071 /* precompute psi */ 00072 if(my_plan.flags & PRE_PSI) 00073 nfft_precompute_psi(&my_plan); 00074 00075 /* precompute full psi */ 00076 if(my_plan.flags & PRE_FULL_PSI) 00077 nfft_precompute_full_psi(&my_plan); 00078 00079 00080 /* compute the adjoint nfft */ 00081 nfft_adjoint(&my_plan); 00082 00083 fout_real=fopen("output_real.dat","w"); 00084 fout_imag=fopen("output_imag.dat","w"); 00085 00086 for (j=0;j<N*N;j++) { 00087 fprintf(fout_real,"%le ",creal(my_plan.f_hat[j])); 00088 fprintf(fout_imag,"%le ",cimag(my_plan.f_hat[j])); 00089 } 00090 00091 fclose(fin); 00092 fclose(fout_real); 00093 fclose(fout_imag); 00094 00095 nfft_finalize(&my_plan); 00096 } 00097 00098 00099 int main(int argc, char **argv) 00100 { 00101 if (argc <= 5) { 00102 printf("usage: ./reconstruct_data_gridding FILENAME N M ITER WEIGHTS\n"); 00103 return 1; 00104 } 00105 reconstruct(argv[1],atoi(argv[2]),atoi(argv[3]),atoi(argv[5])); 00106 00107 return 1; 00108 } 00109 /* \} */