HistogramGenerator Class Reference

#include <HistogramGenerator.h>

Inheritance diagram for HistogramGenerator:

Public Member Functions
virtual double	function (double x)
	The probability density function implementation. More...
	HistogramGenerator (TH1 *histo, const RandomEngine *engine)
	Constructor : initialization of the Random Generator. More...
virtual	~HistogramGenerator ()
	Default destructor. More...
Public Member Functions inherited from BaseNumericalRandomGenerator
	BaseNumericalRandomGenerator (const RandomEngine *engine, double xmin=0., double xmax=1., int n=1000, int iter=6)
double	generate () const
	The random generation according to function() More...
double	generateExp () const
double	generateLin () const
void	initialize ()
	The initialization (numerical integarion, inversion) More...
bool	setSubInterval (double x1, double x2)
	To shoot in a given interval. More...
virtual	~BaseNumericalRandomGenerator ()
	Default destructor. More...

Private Member Functions
double	ersatzt (double x)
	Gamma Function. More...

Private Attributes
TH1 *	myHisto
	Pointer to the histogram. More...
int	nbins
	n bins More...
TAxis *	theXaxis
	the axis More...

Additional Inherited Members
Protected Attributes inherited from BaseNumericalRandomGenerator
double	deltar
std::vector< double >	f
int	iter
int	n
const RandomEngine *	random
double	rmin
std::vector< double >	sampling
double	xmax
double	xmin

Detailed Description

Definition at line 14 of file HistogramGenerator.h.

Constructor & Destructor Documentation

HistogramGenerator::HistogramGenerator ( TH1 *  histo, const RandomEngine *  engine  )

inline

Constructor : initialization of the Random Generator.

Definition at line 19 of file HistogramGenerator.h.

References BaseNumericalRandomGenerator::initialize(), nbins, BaseNumericalRandomGenerator::xmax, and BaseNumericalRandomGenerator::xmin.

                                                               : 
     BaseNumericalRandomGenerator(engine,
                  histo->GetXaxis()->GetXmin(),
                  histo->GetXaxis()->GetXmax(),
                  100000,
                  3),
     myHisto(histo),
     theXaxis(histo->GetXaxis()),
     nbins(histo->GetXaxis()->GetNbins())
  {

    //    std::cout << "Old xmin/xmax = " << xmin << " " << xmax << std::endl;
    // Drop lowest and highest empty bins 
    double du = (xmax-xmin)/(float)nbins;
    // Restrict xmin to meaningful values
    while ( function(xmin) <= 0. ) xmin += du;
    // Restrict xmax to meaningful values
    while ( function(xmax) <= 0. ) xmax -= du;

    if ( xmin != histo->GetXaxis()->GetXmin() ) xmin -= du;
    if ( xmax != histo->GetXaxis()->GetXmax() ) xmax += du;

    //    std::cout << "New xmin/xmax = " << xmin << " " << xmax << std::endl;

    //    std::cout <<" Init " << std::endl;
    initialize();
  }

virtual HistogramGenerator::~HistogramGenerator ( )

inlinevirtual

Default destructor.

Definition at line 48 of file HistogramGenerator.h.

{}

Member Function Documentation

double HistogramGenerator::ersatzt ( double  x )

private

Gamma Function.

Definition at line 5 of file HistogramGenerator.cc.

References myHisto, nbins, and theXaxis.

Referenced by function().

{
  int ibin=theXaxis->FindBin(x);
  //  std::cout << x << " Bin " << ibin << std::endl;
  double x1=myHisto->GetBinLowEdge(ibin);
  double x2=x1+myHisto->GetBinWidth(ibin);
  double y1=myHisto->GetBinContent(ibin);  
  double y2;
  if(ibin<nbins)
    y2=myHisto->GetBinContent(ibin+1);
  else
    y2=y1;
  // std::cout << " X1 " << x1 <<" X2 " << x2 << " Y1 " <<y1 << " Y2 " << y2 << std::endl;
  return y2 + (y1-y2)*(x2-x)/(x2-x1);
}

virtual double HistogramGenerator::function ( double  x )

inlinevirtual

The probability density function implementation.

Implements BaseNumericalRandomGenerator.

Definition at line 51 of file HistogramGenerator.h.

References ersatzt(), and x.

{ return ersatzt(x); }

Member Data Documentation

TH1* HistogramGenerator::myHisto

private

Pointer to the histogram.

Definition at line 55 of file HistogramGenerator.h.

Referenced by ersatzt().

int HistogramGenerator::nbins

private

n bins

Definition at line 61 of file HistogramGenerator.h.

Referenced by python.rootplot.utilities.Hist::__init_TGraph(), python.rootplot.utilities.Hist::__len__(), python.rootplot.root2matplotlib.Hist::_prepare_xaxis(), python.rootplot.root2matplotlib.Hist::_prepare_yaxis(), python.rootplot.utilities.Hist::av_xerr(), python.rootplot.utilities.Hist::av_yerr(), python.rootplot.utilities.Hist::delete_bin(), python.rootplot.utilities.Hist::divide(), ersatzt(), HistogramGenerator(), python.rootplot.utilities.Hist::TGraph(), and python.rootplot.utilities.Hist::TH1F().

TAxis* HistogramGenerator::theXaxis

private

the axis

Definition at line 58 of file HistogramGenerator.h.

Referenced by ersatzt().