fastsum_test.c

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/*
 * Copyright (c) 2002, 2012 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.
 */

/* $Id: fastsum_test.c 3896 2012-10-10 12:19:26Z tovo $ */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#ifdef HAVE_COMPLEX_H
  #include <complex.h>
#endif

#ifdef _OPENMP
  #include <omp.h>
#endif

#include "fastsum.h"
#include "kernels.h"
#include "infft.h"

int main(int argc, char **argv)
{
  int j,k,t;                                         
  int d;                                             
  int N;                                             
  int M;                                             
  int n;                                             
  int m;                                             
  int p;                                             
  char *s;                                           
  double _Complex (*kernel)(double , int , const double *);  
  double c;                                          
  fastsum_plan my_fastsum_plan;                      
  double _Complex *direct;                                   
  ticks t0, t1;                                      
  double time;                                       
  double error=0.0;                                  
  double eps_I;                                      
  double eps_B;                                      
  if (argc!=11)
  {
    printf("\nfastsum_test d N M n m p kernel c eps_I eps_B\n\n");
    printf("  d       dimension                 \n");
    printf("  N       number of source nodes    \n");
    printf("  M       number of target nodes    \n");
    printf("  n       expansion degree          \n");
    printf("  m       cut-off parameter         \n");
    printf("  p       degree of smoothness      \n");
    printf("  kernel  kernel function  (e.g., gaussian)\n");
    printf("  c       kernel parameter          \n");
    printf("  eps_I   inner boundary            \n");
    printf("  eps_B   outer boundary            \n\n");
    exit(-1);
  }
  else
  {
    d=atoi(argv[1]);
    N=atoi(argv[2]); c=1.0/pow((double)N,1.0/(double)d);
    M=atoi(argv[3]);
    n=atoi(argv[4]);
    m=atoi(argv[5]);
    p=atoi(argv[6]);
    s=argv[7];
    c=atof(argv[8]);
    eps_I=atof(argv[9]);
    eps_B=atof(argv[10]);
    if (strcmp(s,"gaussian")==0)
      kernel = gaussian;
    else if (strcmp(s,"multiquadric")==0)
      kernel = multiquadric;
    else if (strcmp(s,"inverse_multiquadric")==0)
      kernel = inverse_multiquadric;
    else if (strcmp(s,"logarithm")==0)
      kernel = logarithm;
    else if (strcmp(s,"thinplate_spline")==0)
      kernel = thinplate_spline;
    else if (strcmp(s,"one_over_square")==0)
      kernel = one_over_square;
    else if (strcmp(s,"one_over_modulus")==0)
      kernel = one_over_modulus;
    else if (strcmp(s,"one_over_x")==0)
      kernel = one_over_x;
    else if (strcmp(s,"inverse_multiquadric3")==0)
      kernel = inverse_multiquadric3;
    else if (strcmp(s,"sinc_kernel")==0)
      kernel = sinc_kernel;
    else if (strcmp(s,"cosc")==0)
      kernel = cosc;
    else if (strcmp(s,"cot")==0)
      kernel = kcot;
    else
    {
      s="multiquadric";
      kernel = multiquadric;
    }
  }
  printf("d=%d, N=%d, M=%d, n=%d, m=%d, p=%d, kernel=%s, c=%g, eps_I=%g, eps_B=%g \n",d,N,M,n,m,p,s,c,eps_I,eps_B);
#ifdef NF_KUB
  printf("nearfield correction using piecewise cubic Lagrange interpolation\n");
#elif defined(NF_QUADR)
  printf("nearfield correction using piecewise quadratic Lagrange interpolation\n");
#elif defined(NF_LIN)
  printf("nearfield correction using piecewise linear Lagrange interpolation\n");
#endif

#ifdef _OPENMP
  #pragma omp parallel
  {
    #pragma omp single
    {
      printf("nthreads=%d\n", omp_get_max_threads());
    }
  }

  fftw_init_threads();
#endif

  fastsum_init_guru(&my_fastsum_plan, d, N, M, kernel, &c, 0, n, m, p, eps_I, eps_B);
  //fastsum_init_guru(&my_fastsum_plan, d, N, M, kernel, &c, NEARFIELD_BOXES, n, m, p, eps_I, eps_B);

  if (my_fastsum_plan.flags & NEARFIELD_BOXES)
    printf("determination of nearfield candidates based on partitioning into boxes\n");
  else
    printf("determination of nearfield candidates based on search tree\n");

  k = 0;
  while (k < N)
  {
    double r_max = 0.25 - my_fastsum_plan.eps_B/2.0;
    double r2 = 0.0;

    for (j=0; j<d; j++)
      my_fastsum_plan.x[k*d+j] = 2.0 * r_max * (double)rand()/(double)RAND_MAX - r_max;

    for (j=0; j<d; j++)
      r2 += my_fastsum_plan.x[k*d+j] * my_fastsum_plan.x[k*d+j];

    if (r2 >= r_max * r_max)
      continue;

    k++;
  }

  for (k=0; k<N; k++)
  {
/*    double r=(0.25-my_fastsum_plan.eps_B/2.0)*pow((double)rand()/(double)RAND_MAX,1.0/d);
    my_fastsum_plan.x[k*d+0] = r;
    for (j=1; j<d; j++)
    {
      double phi=2.0*PI*(double)rand()/(double)RAND_MAX;
      my_fastsum_plan.x[k*d+j] = r;
      for (t=0; t<j; t++)
      {
        my_fastsum_plan.x[k*d+t] *= cos(phi);
      }
      my_fastsum_plan.x[k*d+j] *= sin(phi);
    }
*/
    my_fastsum_plan.alpha[k] = (double)rand()/(double)RAND_MAX + _Complex_I*(double)rand()/(double)RAND_MAX;
  }

  k = 0;
  while (k < M)
  {
    double r_max = 0.25 - my_fastsum_plan.eps_B/2.0;
    double r2 = 0.0;

    for (j=0; j<d; j++)
      my_fastsum_plan.y[k*d+j] = 2.0 * r_max * (double)rand()/(double)RAND_MAX - r_max;

    for (j=0; j<d; j++)
      r2 += my_fastsum_plan.y[k*d+j] * my_fastsum_plan.y[k*d+j];

    if (r2 >= r_max * r_max)
      continue;

    k++;
  }
/*  for (k=0; k<M; k++)
  {
    double r=(0.25-my_fastsum_plan.eps_B/2.0)*pow((double)rand()/(double)RAND_MAX,1.0/d);
    my_fastsum_plan.y[k*d+0] = r;
    for (j=1; j<d; j++)
    {
      double phi=2.0*PI*(double)rand()/(double)RAND_MAX;
      my_fastsum_plan.y[k*d+j] = r;
      for (t=0; t<j; t++)
      {
        my_fastsum_plan.y[k*d+t] *= cos(phi);
      }
      my_fastsum_plan.y[k*d+j] *= sin(phi);
    }
  } */

  printf("direct computation: "); fflush(NULL);
  t0 = getticks();
  fastsum_exact(&my_fastsum_plan);
  t1 = getticks();
  time=nfft_elapsed_seconds(t1,t0);
  printf("%fsec\n",time);

  direct = (double _Complex *)nfft_malloc(my_fastsum_plan.M_total*(sizeof(double _Complex)));
  for (j=0; j<my_fastsum_plan.M_total; j++)
    direct[j]=my_fastsum_plan.f[j];

  printf("pre-computation:    "); fflush(NULL);
  t0 = getticks();
  fastsum_precompute(&my_fastsum_plan);
  t1 = getticks();
  time=nfft_elapsed_seconds(t1,t0);
  printf("%fsec\n",time);

  printf("fast computation:   "); fflush(NULL);
  t0 = getticks();
  fastsum_trafo(&my_fastsum_plan);
  t1 = getticks();
  time=nfft_elapsed_seconds(t1,t0);
  printf("%fsec\n",time);

  error=0.0;
  for (j=0; j<my_fastsum_plan.M_total; j++)
  {
    if (cabs(direct[j]-my_fastsum_plan.f[j])/cabs(direct[j])>error)
      error=cabs(direct[j]-my_fastsum_plan.f[j])/cabs(direct[j]);
  }
  printf("max relative error: %e\n",error);

  fastsum_finalize(&my_fastsum_plan);

  return 0;
}
/* \} */