static void simple_test_nnfft_2d(void) { int j,k; /**< index for nodes and freqencies */ nnfft_plan my_plan; /**< plan for the nfft */ int N[2]; N[0]=12; N[1]=14; /** init an one dimensional plan */ nnfft_init(&my_plan, 2,12*14,19, N); /** init pseudo random nodes */ for(j=0;j<my_plan.M_total;j++) { my_plan.x[2*j]=((double)rand())/((double)RAND_MAX)-0.5; my_plan.x[2*j+1]=((double)rand())/((double)RAND_MAX)-0.5; } /** init pseudo random nodes */ for(j=0;j<my_plan.N_total;j++) { my_plan.v[2*j]=((double)rand())/((double)RAND_MAX)-0.5; my_plan.v[2*j+1]=((double)rand())/((double)RAND_MAX)-0.5; } /** precompute psi, the entries of the matrix B */ if(my_plan.nnfft_flags & PRE_PSI) nnfft_precompute_psi(&my_plan); if(my_plan.nnfft_flags & PRE_FULL_PSI) nnfft_precompute_full_psi(&my_plan); if(my_plan.nnfft_flags & PRE_LIN_PSI) nnfft_precompute_lin_psi(&my_plan); /** precompute phi_hut, the entries of the matrix D */ if(my_plan.nnfft_flags & PRE_PHI_HUT) nnfft_precompute_phi_hut(&my_plan); /** init pseudo random Fourier coefficients and show them */ for(k=0;k<my_plan.N_total;k++) my_plan.f_hat[k] = ((double)rand())/((double)RAND_MAX) + _Complex_I*((double)rand())/((double)RAND_MAX); nfft_vpr_complex(my_plan.f_hat,12, "given Fourier coefficients, vector f_hat (first 12 entries)"); /** direct trafo and show the result */ nnfft_trafo_direct(&my_plan); nfft_vpr_complex(my_plan.f,my_plan.M_total,"ndft, vector f"); /** approx. trafo and show the result */ nnfft_trafo(&my_plan); nfft_vpr_complex(my_plan.f,my_plan.M_total,"nfft, vector f"); /** finalise the one dimensional plan */ nnfft_finalize(&my_plan); }
static void simple_test_adjoint_nnfft_1d(void) { int j; /**< index for nodes and freqencies */ nnfft_plan my_plan; /**< plan for the nfft */ int N[1]; N[0]=12; /** init an one dimensional plan */ nnfft_init(&my_plan, 1, 20, 33, N); /** init pseudo random nodes */ for(j=0;j<my_plan.M_total;j++) { my_plan.x[j]=((double)rand())/((double)RAND_MAX)-0.5; } /** init pseudo random nodes */ for(j=0;j<my_plan.N_total;j++) { my_plan.v[j]=((double)rand())/((double)RAND_MAX)-0.5; } /** precompute psi, the entries of the matrix B */ if(my_plan.nnfft_flags & PRE_PSI) nnfft_precompute_psi(&my_plan); if(my_plan.nnfft_flags & PRE_FULL_PSI) nnfft_precompute_full_psi(&my_plan); if(my_plan.nnfft_flags & PRE_LIN_PSI) nnfft_precompute_lin_psi(&my_plan); /** precompute phi_hut, the entries of the matrix D */ if(my_plan.nnfft_flags & PRE_PHI_HUT) nnfft_precompute_phi_hut(&my_plan); /** init pseudo random Fourier coefficients and show them */ for(j=0;j<my_plan.M_total;j++) my_plan.f[j] = ((double)rand())/((double)RAND_MAX) + _Complex_I*((double)rand())/((double)RAND_MAX); nfft_vpr_complex(my_plan.f,my_plan.M_total,"given Samples, vector f"); /** direct trafo and show the result */ nnfft_adjoint_direct(&my_plan); nfft_vpr_complex(my_plan.f_hat,my_plan.N_total,"adjoint nndft, vector f_hat"); /** approx. trafo and show the result */ nnfft_adjoint(&my_plan); nfft_vpr_complex(my_plan.f_hat,my_plan.N_total,"adjoint nnfft, vector f_hat"); /** finalise the one dimensional plan */ nnfft_finalize(&my_plan); }
/** * reconstruct */ static void reconstruct(char* filename,int N,int M,int iteration, int weight) { int j,k,l; /* some variables */ nnfft_plan my_plan; /* plan for the two dimensional nfft */ solver_plan_complex my_iplan; /* plan for the two dimensional infft */ FILE* fin; /* input file */ FILE* finh; FILE* ftime; FILE* fout_real; /* output file */ FILE* fout_imag; /* output file */ int my_N[3],my_n[3]; /* to init the nfft */ double t0, t1; double t,epsilon=0.0000003; /* epsilon is a the break criterium for the iteration */ unsigned infft_flags = CGNR | PRECOMPUTE_DAMP; /* flags for the infft*/ double time,min_time,max_time,min_inh,max_inh; double real,imag; double *w; double Ts; double W; int N3; int m=2; double sigma = 1.25; w = (double*)nfft_malloc(N*N*sizeof(double)); ftime=fopen("readout_time.dat","r"); finh=fopen("inh.dat","r"); min_time=INT_MAX; max_time=INT_MIN; for(j=0;j<M;j++) { fscanf(ftime,"%le ",&time); if(time<min_time) min_time = time; if(time>max_time) max_time = time; } fclose(ftime); Ts=(min_time+max_time)/2.0; min_inh=INT_MAX; max_inh=INT_MIN; for(j=0;j<N*N;j++) { fscanf(finh,"%le ",&w[j]); if(w[j]<min_inh) min_inh = w[j]; if(w[j]>max_inh) max_inh = w[j]; } fclose(finh); N3=ceil((MAX(fabs(min_inh),fabs(max_inh))*(max_time-min_time)/2.0)*4); W=MAX(fabs(min_inh),fabs(max_inh))*2.0; fprintf(stderr,"3: %i %e %e %e %e %e %e\n",N3,W,min_inh,max_inh,min_time,max_time,Ts); /* initialise my_plan */ my_N[0]=N;my_n[0]=ceil(N*sigma); my_N[1]=N; my_n[1]=ceil(N*sigma); my_N[2]=N3; my_n[2]=ceil(N3*sigma); nnfft_init_guru(&my_plan, 3, N*N, M, my_N,my_n,m, PRE_PSI| PRE_PHI_HUT| MALLOC_X| MALLOC_V| MALLOC_F_HAT| MALLOC_F ); /* precompute lin psi if set */ if(my_plan.nnfft_flags & PRE_LIN_PSI) nnfft_precompute_lin_psi(&my_plan); /* set the flags for the infft*/ if (weight) infft_flags = infft_flags | PRECOMPUTE_WEIGHT; /* initialise my_iplan, advanced */ solver_init_advanced_complex(&my_iplan,(nfft_mv_plan_complex*)(&my_plan), infft_flags ); /* get the weights */ if(my_iplan.flags & PRECOMPUTE_WEIGHT) { fin=fopen("weights.dat","r"); for(j=0;j<my_plan.M_total;j++) { fscanf(fin,"%le ",&my_iplan.w[j]); } fclose(fin); } /* get the damping factors */ if(my_iplan.flags & PRECOMPUTE_DAMP) { for(j=0;j<N;j++){ for(k=0;k<N;k++) { int j2= j-N/2; int k2= k-N/2; double r=sqrt(j2*j2+k2*k2); if(r>(double) N/2) my_iplan.w_hat[j*N+k]=0.0; else my_iplan.w_hat[j*N+k]=1.0; } } } /* open the input file */ fin=fopen(filename,"r"); ftime=fopen("readout_time.dat","r"); for(j=0;j<my_plan.M_total;j++) { fscanf(fin,"%le %le %le %le ",&my_plan.x[3*j+0],&my_plan.x[3*j+1],&real,&imag); my_iplan.y[j]=real+ _Complex_I*imag; fscanf(ftime,"%le ",&my_plan.x[3*j+2]); my_plan.x[3*j+2] = (my_plan.x[3*j+2]-Ts)*W/N3; } for(j=0;j<N;j++) { for(l=0;l<N;l++) { my_plan.v[3*(N*j+l)+0]=(((double) j) -(((double) N)/2.0))/((double) N); my_plan.v[3*(N*j+l)+1]=(((double) l) -(((double) N)/2.0))/((double) N); my_plan.v[3*(N*j+l)+2] = w[N*j+l]/W ; } } /* precompute psi */ if(my_plan.nnfft_flags & PRE_PSI) { nnfft_precompute_psi(&my_plan); if(my_plan.nnfft_flags & PRE_FULL_PSI) nnfft_precompute_full_psi(&my_plan); } if(my_plan.nnfft_flags & PRE_PHI_HUT) nnfft_precompute_phi_hut(&my_plan); /* init some guess */ for(k=0;k<my_plan.N_total;k++) { my_iplan.f_hat_iter[k]=0.0; } t0 = nfft_clock_gettime_seconds(); /* inverse trafo */ solver_before_loop_complex(&my_iplan); for(l=0;l<iteration;l++) { /* break if dot_r_iter is smaller than epsilon*/ if(my_iplan.dot_r_iter<epsilon) break; fprintf(stderr,"%e, %i of %i\n",sqrt(my_iplan.dot_r_iter), l+1,iteration); solver_loop_one_step_complex(&my_iplan); } t1 = nfft_clock_gettime_seconds(); t = t1-t0; fout_real=fopen("output_real.dat","w"); fout_imag=fopen("output_imag.dat","w"); for(k=0;k<my_plan.N_total;k++) { my_iplan.f_hat_iter[k]*=cexp(2.0*_Complex_I*M_PI*Ts*w[k]); fprintf(fout_real,"%le ", creal(my_iplan.f_hat_iter[k])); fprintf(fout_imag,"%le ", cimag(my_iplan.f_hat_iter[k])); } fclose(fout_real); fclose(fout_imag); /* finalize the infft */ solver_finalize_complex(&my_iplan); /* finalize the nfft */ nnfft_finalize(&my_plan); nfft_free(w); }
void accuracy(int d) { int m,t; nnfft_plan my_plan; double complex *slow; int N[d],n[d]; int M_total,N_total; M_total=10000;N_total=1; slow=(double complex*)fftw_malloc(M_total*sizeof(double complex)); for(t=0; t<d; t++) { N[t]=(1<<(12/d)); n[t]=2*N[t]; N_total*=N[t]; } /** init a plan */ for(m=0; m<10; m++) { nnfft_init_guru(&my_plan, d, N_total, M_total, N, n, m, PRE_PSI| PRE_PHI_HUT| MALLOC_X| MALLOC_V| MALLOC_F_HAT| MALLOC_F); /** init pseudo random nodes */ nfft_vrand_shifted_unit_double(my_plan.x, d*my_plan.M_total); nfft_vrand_shifted_unit_double(my_plan.v, d*my_plan.N_total); /** precompute psi, the entries of the matrix B */ if(my_plan.nnfft_flags & PRE_PSI) nnfft_precompute_psi(&my_plan); if(my_plan.nnfft_flags & PRE_LIN_PSI) nnfft_precompute_lin_psi(&my_plan); if(my_plan.nnfft_flags & PRE_FULL_PSI) nnfft_precompute_full_psi(&my_plan); /** precompute psi, the entries of the matrix D */ if(my_plan.nnfft_flags & PRE_PHI_HUT) nnfft_precompute_phi_hut(&my_plan); /** init pseudo random Fourier coefficients */ nfft_vrand_unit_complex(my_plan.f_hat, my_plan.N_total); /** direct trafo and show the result */ nndft_trafo(&my_plan); NFFT_SWAP_complex(my_plan.f,slow); /** approx. trafo and show the result */ nnfft_trafo(&my_plan); printf("%e, %e\n", nfft_error_l_infty_complex(slow, my_plan.f, M_total), nfft_error_l_infty_1_complex(slow, my_plan.f, M_total, my_plan.f_hat, my_plan.N_total)); /** finalise the one dimensional plan */ nnfft_finalize(&my_plan); } }