source: trunk/test/interpolation_test.cc @ 1656

// $Id: interpolation_test.cc 1656 2008-12-17 13:52:51Z jari $

/*
  Copyright (C) 2008 Jari Häkkinen

  This file is part of the yat library, http://dev.thep.lu.se/yat

  The yat library 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 3 of the
  License, or (at your option) any later version.

  The yat library 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 yat. If not, see <http://www.gnu.org/licenses/>.
*/

#include "Suite.h"

#include "yat/regression/AkimaInterpolation.h"
#include "yat/regression/AkimaPeriodicInterpolation.h"
#include "yat/regression/CSplineInterpolation.h"
#include "yat/regression/CSplinePeriodicInterpolation.h"
#include "yat/regression/LinearInterpolation.h"
#include "yat/regression/PolynomialInterpolation.h"
#include "yat/utility/Vector.h"
#include "yat/utility/VectorConstView.h"

#include <cmath>

int main(int argc, char* argv[])
{
  using namespace theplu::yat;
  using namespace theplu::yat::regression;

  test::Suite suite(argc, argv);

  /*
    The test data is computed with R version 2.7.2 (2008-08-25) on
    MacBook Pro Intel CPU running MacOSX 10.5.5

    x <- c(13,17,19,22,27,35)
    y <- c(100,97,111,120,117,103)
    cspline <- splinefun(x,y,"natural")
    w <- seq(15,25,1)
    z <- cspline(w)
    z
    [1]  94.11579  93.91382  97.00000 103.66776 111.00000 116.02563 118.76822
    [8] 120.00000 120.38499 120.15443 119.43138
  */

  utility::Vector x(6);
  utility::Vector y(6);
  x(0)= 13; x(1)= 17; x(2)= 19; x(3)= 22; x(4)= 27; x(5)= 35;
  y(0)=100; y(1)= 97; y(2)=111; y(3)=120; y(4)=117; y(5)=103;

  CSplineInterpolation cspline(x,y);

  utility::Vector w(11);
  utility::Vector z(11);
  w( 0)=15;  z( 0)= 94.11579;
  w( 1)=16;  z( 1)= 93.91382;
  w( 2)=17;  z( 2)= 97;
  w( 3)=18;  z( 3)=103.66776;
  w( 4)=19;  z( 4)=111;
  w( 5)=20;  z( 5)=116.02563;
  w( 6)=21;  z( 6)=118.76822;
  w( 7)=22;  z( 7)=120;
  w( 8)=23;  z( 8)=120.38499;
  w( 9)=24;  z( 9)=120.15443;
  w(10)=25;  z(10)=119.43138;

  for (size_t i=0; i<w.size(); ++i) {
    if ( fabs(cspline.evaluate(w(i))-z(i)) > 1e-5) {
      suite.err() << "cspline test failed for i=" << i << std::endl;
      suite.err() << " difference between target and interpolation too large: "
                  << fabs(cspline.evaluate(w(i))-z(i)) << std::endl;
      suite.add(false);
    }
    // Check for errors
    if (cspline.error_status()) {
      suite.err() << "cspline test failed with GSL_EDOM error" << std::endl;
      suite.add(false);
    }
  }

  // An error should be generated, if not test fails
  cspline.evaluate(w(0)-5);
  if (!cspline.error_status()) {
    suite.err() << "cspline test failed no GSL_EDOM error occured" << std::endl;
    suite.add(false);
  }

  // lazy testing, at least try to create the objects
  AkimaInterpolation(x,y);
  AkimaPeriodicInterpolation(x,y);
  CSplinePeriodicInterpolation(x,y);
  LinearInterpolation(x,y);
  PolynomialInterpolation(x,y);

  return suite.return_value();
}