nsfft/simple_test.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 <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <complex.h>
#include "nfft3.h"
static void simple_test_nsfft(int d, int J, int M)
{
int K=12;
nsfft_plan p;
nsfft_init(&p, d, J, M, 6, NSDFT);
nsfft_init_random_nodes_coeffs(&p);
nfft_vpr_complex(p.f_hat, K, "frequencies, vector f_hat (first few entries)");
nsfft_trafo_direct(&p);
nfft_vpr_complex(p.f, K, "nsdft, vector f (first few entries)");
nsfft_trafo(&p);
nfft_vpr_complex(p.f, K, "nsfft, vector f (first few entries)");
nsfft_adjoint_direct(&p);
nfft_vpr_complex(p.f_hat, K, "adjoint nsdft, vector f_hat, (first few entries)");
nsfft_adjoint(&p);
nfft_vpr_complex(p.f_hat, K, "adjoint nsfft, vector f_hat, (first few entries)");
nsfft_finalize(&p);
}
int main(int argc,char **argv)
{
int d, J, M;
system("clear");
printf("1) computing a two dimensional nsdft, nsfft and adjoints\n\n");
d=2;
J=5;
M=(J+4)*nfft_exp2i(J+1);
simple_test_nsfft(d,J,M);
getc(stdin);
system("clear");
printf("2) computing a three dimensional nsdft, nsfft and adjoints\n\n");
d=3;
J=5;
M=6*nfft_exp2i(J)*(nfft_exp2i((J+1)/2+1)-1)+nfft_exp2i(3*(J/2+1));
simple_test_nsfft(d,J,M);
return 1;
}
nsfft_init
void nsfft_init(nsfft_plan *ths, int d, int J, int M, int m, unsigned flags)
Definition: nsfft.c:1778
nsfft_plan::f
fftw_complex * f
Samples.
Definition: nfft3.h:475
nfft_vpr_complex
void nfft_vpr_complex(fftw_complex *x, const NFFT_INT n, const char *text)
Print complex vector to standard output.
nsfft_init_random_nodes_coeffs
void nsfft_init_random_nodes_coeffs(nsfft_plan *ths)
Definition: nsfft.c:723
nsfft_adjoint
void nsfft_adjoint(nsfft_plan *ths)
Definition: nsfft.c:1549
nfft3.h
Header file for the nfft3 library.
nsfft_finalize
void nsfft_finalize(nsfft_plan *ths)
Definition: nsfft.c:1885
NSDFT
#define NSDFT
Definition: nfft3.h:476
nsfft_trafo
void nsfft_trafo(nsfft_plan *ths)
Definition: nsfft.c:1541
nsfft_plan
data structure for an NSFFT (nonequispaced sparse fast Fourier transform) plan with double precision ...
Definition: nfft3.h:475
nsfft_plan::f_hat
fftw_complex * f_hat
Fourier coefficients.
Definition: nfft3.h:475