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/*
* 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 <math.h>
#include <stdlib.h>
#include <complex.h>
#include "nfft3.h"
/** Swap two vectors. */
#define CSWAP(x,y) {double _Complex * NFFT_SWAP_temp__; \
NFFT_SWAP_temp__=(x); (x)=(y); (y)=NFFT_SWAP_temp__;}
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*)nfft_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 */
nnfft_trafo_direct(&my_plan);
CSWAP(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);
}
}
int main(void)
{
int d;
for(d=1; d<4; d++)
accuracy(d);
return 1;
}
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