/**********************************************************************
  *                                                                    *
  * 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/Ext/Defaults.h"
#include "StatTools/Fit/Ext/Defaults.h"
#include "StatTools/Fit/Chi2.h"
#include "StatTools/Fit/Chi2Fitter.h"
#include "StatTools/ToyMC/Experiment.h"
#include "StatTools/Funct/Function.h"
#include "StatTools/Funct/Parameter.h"
#include "StatTools/Pdf/RandomGeneratorConstant.h"
#include "StatTools/Pdf/Pdf.h"
#include "StatTools/Pdf/RandomGeneratorSample.h"
#include "TFile.h"
#include "TH1.h"

using namespace std;
using namespace Fit;
using namespace Funct;
using namespace ToyMC;

template<typename T> 
struct functor {
  static double f( double * x, double * ) { return (*_t)( *x ); }
  static void set( const T& t ) { _t = & t; }
private:
  static T const * _t;
};

template<typename T> 
T const * functor<T>::_t = 0;

struct SinPdf : public Pdf::PdfNoNormalization< X > {
  template< typename F > SinPdf ( const F& f ) : 
    Pdf::PdfNoNormalization< X, Expression >( f ) { }
};

RANDOM_GENERATOR_SAMPLE( SinPdf, 1024, 0.001, 15 )

int main()
{
  X x;
  SinPdf pdf( sqr( sin(x) / x ) );
  UniformPartition partition( 100, 0.001, 15 ); 
  const int bins = partition.bins();
  // const double binw = partition.binWidth();

  TFile file( "testfunctfit2.root", "RECREATE" );
  TH1F histo( "signal", "(sin(x)/x=^2", bins, 0.001, 15 );

  Pdf::Constant<unsigned> n( 10000 );
  Experiment< Pdf::Constant<unsigned>, SinPdf > experiment( n, pdf );
  SampleErr<double> sample( bins );
  experiment.generate( sample, partition );
  int bin = 1;
  for( SampleErr<double>::const_iterator i = sample.begin(); 
       i != sample.end(); i++, bin++ )
  {
    double n = i->content, dn = i->error;
    histo.SetBinContent( bin, n );
    histo.SetBinError( bin, dn );
  }
  histo.Write();

  Parameter fit_constant( 1000 );
  Parameter fit_omega( 1 );
  Function< X > f( fit_constant * sqr( sin( fit_omega * x ) / ( fit_omega * x ) ) );
  Chi2< Function< X > > chi2( f, partition );
  Chi2Fitter< Chi2< Function< X > > > fit( chi2 );
  fit.addParameter( "const", fit_constant.ptr(), 0, 100000 );
  fit.addParameter( "omega", fit_omega.ptr(), 0, 10 );

  cout << "intial function : " << endl << f << endl;
  for ( double x = 0.001; x <= 15; x += 1 )
    cout << "pdf("<<x<<")="<<pdf(x)<<endl;

  double par[] = { fit_constant, fit_omega };
  double err[] = { 1, 0.00001 };
  fit.fit( par, err, sample );
  fit_constant = par[ 0 ];
  fit_omega = par[ 1 ];

  cout << "fit function : " << endl << f << endl;
  for ( double x = 0.001; x <= 15; x += 1 )
    cout << "f("<<x<<")="<<pdf(x)<<endl;
  cout << "fit values: " << endl;
  cout << " 0) const   " << par[ 0 ] << " +/- " << err[ 0 ] << endl;
  cout << " 1) omega   " << par[ 1 ] << " +/- " << err[ 1 ] << endl;

  functor< Function< X > >::set( f );
  TF1 rootfit( "fit", functor< Function< X > >::f, 0.001, 15 );
  rootfit.Write();

  return 0;
}