ExampleGSL.cpp

Example for usage of GSL, GNU Scientific Library

Author

MIP

/* 
This file is part of the BIAS library (Basic ImageAlgorithmS).

Copyright (C) 2003-2009    (see file CONTACT for details)
Multimediale Systeme der Informationsverarbeitung
Institut fuer Informatik
Christian-Albrechts-Universitaet Kiel


BIAS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

BIAS 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with BIAS; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/


/** @example ExampleGSL.cpp
    @relates GSL
    @ingroup g_examples    
    @brief   Example for usage of GSL, GNU Scientific Library
    @author MIP
*/


#include <bias_config.h>
#ifdef BIAS_HAVE_GSL

#include <Base/Math/Random.hh>
#include <MathAlgo/GSL.hh>


using namespace BIAS;
using namespace std;


// dart smoketest: Does calling GSL directly compute expecteed values? (JW)
#  include <gsl/gsl_cdf.h>
int TestGSL(){
  const double x          (5.678);
  const double nu         (3.21);
  const double groundtruth(0.85341575204989784);
  const double eps        (0.0000000000001);
  // call func directly to test lib instead of wrapping
  double val = gsl_cdf_chisq_P (x, nu);
  //cout<<"val="<<setprecision(30)<<val<<endl;
  // TODO: robust comparison against ground truth precomputed value
  if (fabs(val-groundtruth)>eps){
    return -1; // failure
  } else  {
    return 0; // OK
  }
}


int main(int /*argc*/, char ** /*argv*/ )
{
  Random rand;
  const int count=100;
  const int deg_freedom = 2;
  double x;

  for (int i=0; i<count; i++){
    x = rand.GetUniformDistributed(0.0, 1.0);
    cout << setw(13) << setprecision(3) << x
      << setw(13) << setprecision(3) 
      << BIAS::InvChiSquareCulmProbFun(x, deg_freedom)  /* from BIAS/MathAlgo/GSL.hh */
      << endl;
  }

  return TestGSL(); // darttest
  //return 0;
}
#endif // BIAS_HAVE_GSL