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NFFT
3.3.1
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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 Z, int weight ,fftw_complex *mem) 00038 { 00039 int j,k,z; /* some variables */ 00040 double weights; /* store one weight temporary */ 00041 double tmp; /* tmp to read the obsolent z from the input file */ 00042 double real,imag; /* to read the real and imag part of a complex number */ 00043 nfft_plan my_plan; /* plan for the two dimensional nfft */ 00044 int my_N[2],my_n[2]; /* to init the nfft */ 00045 FILE* fin; /* input file */ 00046 FILE* fweight; /* input file for the weights */ 00047 00048 /* initialise my_plan */ 00049 my_N[0]=N; my_n[0]=ceil(N*1.2); 00050 my_N[1]=N; my_n[1]=ceil(N*1.2); 00051 nfft_init_guru(&my_plan, 2, my_N, M/Z, my_n, 6, PRE_PHI_HUT| PRE_PSI| 00052 MALLOC_X| MALLOC_F_HAT| MALLOC_F| 00053 FFTW_INIT| FFT_OUT_OF_PLACE, 00054 FFTW_MEASURE| FFTW_DESTROY_INPUT); 00055 00056 /* precompute lin psi if set */ 00057 if(my_plan.flags & PRE_LIN_PSI) 00058 nfft_precompute_lin_psi(&my_plan); 00059 00060 fin=fopen(filename,"r"); 00061 00062 for(z=0;z<Z;z++) { 00063 fweight=fopen("weights.dat","r"); 00064 for(j=0;j<my_plan.M_total;j++) 00065 { 00066 fscanf(fweight,"%le ",&weights); 00067 fscanf(fin,"%le %le %le %le %le", 00068 &my_plan.x[2*j+0],&my_plan.x[2*j+1],&tmp,&real,&imag); 00069 my_plan.f[j] = real + _Complex_I*imag; 00070 if(weight) 00071 my_plan.f[j] = my_plan.f[j] * weights; 00072 } 00073 fclose(fweight); 00074 00075 /* precompute psi if set just one time because the knots equal each slice */ 00076 if(z==0 && my_plan.flags & PRE_PSI) 00077 nfft_precompute_psi(&my_plan); 00078 00079 /* precompute full psi if set just one time because the knots equal each slice */ 00080 if(z==0 && my_plan.flags & PRE_FULL_PSI) 00081 nfft_precompute_full_psi(&my_plan); 00082 00083 /* compute the adjoint nfft */ 00084 nfft_adjoint(&my_plan); 00085 00086 for(k=0;k<my_plan.N_total;k++) { 00087 /* write every slice in the memory. 00088 here we make an fftshift direct */ 00089 mem[(Z*N*N/2+z*N*N+ k)%(Z*N*N)] = my_plan.f_hat[k]; 00090 } 00091 } 00092 fclose(fin); 00093 00094 nfft_finalize(&my_plan); 00095 } 00096 00101 static void print(int N,int M,int Z, fftw_complex *mem) 00102 { 00103 int i,j; 00104 FILE* fout_real; 00105 FILE* fout_imag; 00106 fout_real=fopen("output_real.dat","w"); 00107 fout_imag=fopen("output_imag.dat","w"); 00108 00109 for(i=0;i<Z;i++) { 00110 for (j=0;j<N*N;j++) { 00111 fprintf(fout_real,"%le ",creal(mem[(Z*N*N/2+i*N*N+ j)%(Z*N*N)]) /Z); 00112 fprintf(fout_imag,"%le ",cimag(mem[(Z*N*N/2+i*N*N+ j)%(Z*N*N)]) /Z); 00113 } 00114 fprintf(fout_real,"\n"); 00115 fprintf(fout_imag,"\n"); 00116 } 00117 00118 fclose(fout_real); 00119 fclose(fout_imag); 00120 } 00121 00122 00123 int main(int argc, char **argv) 00124 { 00125 fftw_complex *mem; 00126 fftw_plan plan; 00127 int N,M,Z; 00128 00129 if (argc <= 6) { 00130 printf("usage: ./reconstruct_data_gridding FILENAME N M Z ITER WEIGHTS\n"); 00131 return 1; 00132 } 00133 00134 N=atoi(argv[2]); 00135 M=atoi(argv[3]); 00136 Z=atoi(argv[4]); 00137 00138 /* Allocate memory to hold every slice in memory after the 00139 2D-infft */ 00140 mem = (fftw_complex*) nfft_malloc(sizeof(fftw_complex) * atoi(argv[2]) * atoi(argv[2]) * atoi(argv[4])); 00141 00142 /* Create plan for the 1d-ifft */ 00143 plan = fftw_plan_many_dft(1, &Z, N*N, 00144 mem, NULL, 00145 N*N, 1, 00146 mem, NULL, 00147 N*N,1 , 00148 FFTW_BACKWARD, FFTW_MEASURE); 00149 00150 /* execute the 2d-nfft's */ 00151 reconstruct(argv[1],atoi(argv[2]),atoi(argv[3]),atoi(argv[4]),atoi(argv[6]),mem); 00152 00153 /* execute the 1d-fft's */ 00154 fftw_execute(plan); 00155 00156 /* write the memory back in files */ 00157 print(N,M,Z, mem); 00158 00159 /* free memory */ 00160 nfft_free(mem); 00161 00162 return 1; 00163 } 00164 /* \} */