/**********************************************************************
  *                                                                    *
  * Copyright (c) 2003 INFN - Sezione di Napoli                        *
  *                                                                    *
  * For more information (including a list of authors) see             *
  * the README file                                                    *
  *                                                                    *
  * This 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 2     *
  * of the License, or (at your option) any later version.             *
  *                                                                    *
  * This 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 this library (see file COPYING); if not, write to the   *
  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,        *
  * Boston, MA 02111-1307 USA, or contact the authors.                 *
  *                                                                    *
  **********************************************************************/
#include "StatTools/Pdf/Gaussian.h"
#include <cmath>
#include "StatTools/Funct/Math.h"

namespace Pdf {

double Gaussian::operator()( double x ) const  {
  static const double norm( 1 / sqrt( 2 * M_PI ) );
  double arg = ( x - mean ) / sigma;
  return exp( -0.5 * arg * arg ) * norm / sigma;
}

}