musrfit/src/tests/minuit2example/PGlobalChiSquare.cpp

85 lines
2.9 KiB
C++

/***************************************************************************
PGlobalChiSquare.cpp
Author: Andreas Suter
e-mail: andreas.suter@psi.ch
$Id$
***************************************************************************/
/***************************************************************************
* Copyright (C) 2007 by Andreas Suter *
* andreas.suter@psi.ch *
* *
* 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., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#include <math.h>
#include <iostream>
#include "PGlobalChiSquare.h"
namespace ROOT {
namespace Minuit2 {
//--------------------------------------------------------------------------
/**
* <p>
*/
PGlobalChiSquare::PGlobalChiSquare(PRunList &runList)
{
fRunList = runList;
}
//--------------------------------------------------------------------------
/**
* <p>
*/
PGlobalChiSquare::~PGlobalChiSquare()
{
}
//--------------------------------------------------------------------------
/**
* <p>
*
* \param par
*/
double PGlobalChiSquare::operator()(const std::vector<double>& par) const
{
double chi2 = 0.0;
double funcValue;
double diff;
// calculate chi2 for the given model
for (unsigned int i=0; i<fRunList.size(); i++) { // run loop
for (unsigned int j=0; j<fRunList[i].fTime.size(); j++) { // data loop
funcValue = par[i]*exp(-par[2]*fRunList[i].fTime[j]); // par[i] since par[0] = ampl of run 0, etc.
diff = funcValue - fRunList[i].fValue[j];
chi2 += diff*diff/(fRunList[i].fError[j]*fRunList[i].fError[j]);
}
}
return chi2;
}
} // namespace Minuit2
} // namespace ROOT