generate::hist_generator Class Reference

generate a distribution according to an input histogram (after smoothing) More...

#include <generate.h>

Inheritance diagram for generate::hist_generator:

Collaboration diagram for generate::hist_generator:

Public Member Functions
	hist_generator (TH1D *h, bool smooth_=true)
	hist_generator (const hist_generator &)=delete
hist_generator	operator= (const hist_generator &)=delete
virtual	~hist_generator ()
double	generate () const
	actually generate a random number from the distribution
TH1D *	histogram ()
TH1D *	rawhistogram ()
TH1D *	smoothhistogram ()

Private Member Functions
int	getbin (double y) const
double	invert (double y) const

Private Attributes
std::vector< double >	m_y
std::vector< double >	m_x
std::vector< double >	m_dx
std::vector< double >	m_dy
std::vector< double >	m_dxdy
TH1D *	m_s
TH1D *	m_raw
TH1D *	m_smooth
BasicRandom *	m_random

Detailed Description

generate a distribution according to an input histogram (after smoothing)

Definition at line 72 of file generate.h.

Constructor & Destructor Documentation

hist_generator() [1/2]

generate::hist_generator::hist_generator	(	TH1D *	h,
		bool	smooth_ = true )

save the original histogram (should save a copy ho hum)

smooth the original

else simply clone the original

generate a pdf from the smoothed distribution

assign the actual generator use a shared generator

use a dedicated generator mrandom = new BasicRandom(false);

Definition at line 231 of file generate.cxx.

                                                       : m_random(0) {
    
  m_raw = h;
  
  if ( smooth_ ) {
    m_smooth = smooth( h );
  }
  else { 
    m_smooth = (TH1D*)h->Clone( (std::string(h->GetName())+"-smooth").c_str() );
    m_smooth->SetDirectory(0);
  }
 
  
  m_s = PDF( m_smooth );
  delete m_smooth;
  
  m_s->SetMinimum(0);
  m_s->SetMaximum(1);
  
  m_y.push_back( 0 );
  m_x.push_back( m_s->GetBinLowEdge(1) );
  
  
  for ( int i=1 ; i<=m_s->GetNbinsX() ; i++ ) {
    m_x.push_back( m_s->GetBinLowEdge(i+1) );
    m_y.push_back( m_s->GetBinContent(i) );
  }
  
  m_dy.resize(m_x.size());
  m_dx.resize(m_x.size());
  m_dxdy.resize(m_x.size());
  
  //    std::cout << "calculating gradients ..." << std::endl;
  
  for ( unsigned i=0 ; i<m_y.size()-1 ; i++ ) {
      double dy = m_y[i+1] - m_y[i];
      double dx = m_x[i+1] - m_x[i];
 
      double dxdy = dx/dy;
 
      m_dy[i] = dy;
      m_dx[i] = dx;
      m_dxdy[i] = dxdy;
  }
  
  m_random = new BasicRandom(true);
  
}

hist_generator() [2/2]

generate::hist_generator::hist_generator ( const hist_generator & )

delete

~hist_generator()

virtual generate::hist_generator::~hist_generator ( )

inlinevirtual

Definition at line 81 of file generate.h.

{ delete m_s; if ( m_random ) delete m_random; }

Member Function Documentation

generate()

double generate::hist_generator::generate ( ) const

inlinevirtual

actually generate a random number from the distribution

Implements generate::generator_base.

Definition at line 84 of file generate.h.

                          {
    return invert(m_random->uniform());
  }

getbin()

int generate::hist_generator::getbin ( double y ) const

inlineprivate

Definition at line 94 of file generate.h.

                               {
    for ( unsigned i=0 ; i<m_y.size() ; i++ ) if ( y<=m_y[i] ) return i;
    return m_y.size()-1;
  } 

histogram()

TH1D * generate::hist_generator::histogram ( )

inline

Definition at line 88 of file generate.h.

{ return m_s; }

invert()

double generate::hist_generator::invert ( double y ) const

inlineprivate

Definition at line 99 of file generate.h.

                                  {
    int i = getbin(y);
    if ( i==0 ) return 0;
    else return (y-m_y[i-1])*m_dxdy[i-1]+m_x[i-1];
  }

operator=()

hist_generator generate::hist_generator::operator= ( const hist_generator & )

delete

rawhistogram()

TH1D * generate::hist_generator::rawhistogram ( )

inline

Definition at line 89 of file generate.h.

{ return m_raw; }

smoothhistogram()

TH1D * generate::hist_generator::smoothhistogram ( )

inline

Definition at line 90 of file generate.h.

{ return m_smooth; }

Member Data Documentation

m_dx

std::vector<double> generate::hist_generator::m_dx

private

Definition at line 112 of file generate.h.

m_dxdy

std::vector<double> generate::hist_generator::m_dxdy

private

Definition at line 115 of file generate.h.

m_dy

std::vector<double> generate::hist_generator::m_dy

private

Definition at line 113 of file generate.h.

m_random

BasicRandom* generate::hist_generator::m_random

private

Definition at line 121 of file generate.h.

m_raw

TH1D* generate::hist_generator::m_raw

private

Definition at line 118 of file generate.h.

m_s

TH1D* generate::hist_generator::m_s

private

Definition at line 117 of file generate.h.

m_smooth

TH1D* generate::hist_generator::m_smooth

private

Definition at line 119 of file generate.h.

m_x

std::vector<double> generate::hist_generator::m_x

private

Definition at line 109 of file generate.h.

m_y

std::vector<double> generate::hist_generator::m_y

private

Definition at line 108 of file generate.h.

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The documentation for this class was generated from the following files:

• generate.h
• generate.cxx