The collection of trivial functions to access the statistical information for the histograms. More...

#include <GaudiUtils/HistoStats.h>

Static Public Member Functions
static double	moment (const AIDA::IHistogram1D *histo, const unsigned int order, const double value=0)
	get the "bin-by-bin"-moment around the specified "value"
static double	momentErr (const AIDA::IHistogram1D *histo, const unsigned int order)
	evaluate the uncertanty for 'bin-by-bin'-moment
static double	centralMoment (const AIDA::IHistogram1D *histo, const unsigned int order)
	evaluate the 'bin-by-bin'-central moment (around the mean value)
static double	centralMomentErr (const AIDA::IHistogram1D *histo, const unsigned int order)
	evaluate the uncertanty for 'bin-by-bin'-central moment (around the mean value) ( the uncertanty is calculated with O(1/n2) precision)
static double	skewness (const AIDA::IHistogram1D *histo)
	get the skewness for the histogram
static double	skewnessErr (const AIDA::IHistogram1D *histo)
	get the error in skewness for the histogram
static double	kurtosis (const AIDA::IHistogram1D *histo)
	get the kurtosis for the histogram
static double	kurtosisErr (const AIDA::IHistogram1D *histo)
	get the error in kurtosis for the histogram
static double	mean (const AIDA::IHistogram1D *histo)
	get the mean value for the histogram (just for completeness)
static double	meanErr (const AIDA::IHistogram1D *histo)
	get an error in the mean value
static double	rms (const AIDA::IHistogram1D *histo)
	get the rms value for the histogram (just for completeness)
static double	rmsErr (const AIDA::IHistogram1D *histo)
	get an error in the rms value
static double	nEff (const AIDA::IHistogram1D *histo)
	get the effective entries (just for completeness)
static double	sumBinHeightErr (const AIDA::IHistogram1D *histo)
	get an error in the sum bin height ("in-range integral")
static double	sumAllBinHeightErr (const AIDA::IHistogram1D *histo)
	get an error in the sum of all bin height ("integral")
static double	overflowEntriesFrac (const AIDA::IHistogram1D *histo)
	the fraction of overflow entries (useful for shape comparison)
static double	underflowEntriesFrac (const AIDA::IHistogram1D *histo)
	the fraction of underflow entries (useful for shape comparison)
static double	overflowEntriesFracErr (const AIDA::IHistogram1D *histo)
	error on fraction of overflow entries (useful for shape comparison)
static double	underflowEntriesFracErr (const AIDA::IHistogram1D *histo)
	the error on fraction of underflow entries (useful for shape comparison)
static double	overflowIntegralFrac (const AIDA::IHistogram1D *histo)
	the fraction of overflow intergal (useful for shape comparison)
static double	underflowIntegralFrac (const AIDA::IHistogram1D *histo)
	the fraction of underflow integral (useful for shape comparison)
static double	overflowIntegralFracErr (const AIDA::IHistogram1D *histo)
	the error on fraction of overflow intergal
static double	underflowIntegralFracErr (const AIDA::IHistogram1D *histo)
	the error on fraction of underflow integral
static long	nEntries (const AIDA::IHistogram1D *histo, const int imax)
	get number of entries in histogram up to the certain bin (not-included)
static long	nEntries (const AIDA::IHistogram1D *histo, const int imin, const int imax)
	get number of entries in histogram form the certain minimal bin up to the certain maximal bin (not-included)
static double	nEntriesFrac (const AIDA::IHistogram1D *histo, const int imax)
	get the fraction of entries in histogram up to the certain bin (not-included)
static double	nEntriesFrac (const AIDA::IHistogram1D *histo, const int imin, const int imax)
	get fraction of entries in histogram form the certain minimal bin up to the certain maximal bin (not-included)
static double	nEntriesFracErr (const AIDA::IHistogram1D *histo, const int imax)
	get the (binominal) error for the fraction of entries in histogram up to the certain bin (not-included)
static double	nEntriesFracErr (const AIDA::IHistogram1D *histo, const int imin, const int imax)
	get the (binomial) error for the fraction of entries in histogram from the certain minimal bin up to the certain maximal bin (not-included)

Detailed Description

The collection of trivial functions to access the statistical information for the histograms.

Author:: Vanya BELYAEV ibelyaev@physics.syr.edu

Date:: 2007-08-06

Definition at line 31 of file HistoStats.h.

Member Function Documentation

double Gaudi::Utils::HistoStats::centralMoment	(	const AIDA::IHistogram1D *	histo,
		const unsigned int	order
	)		`[static]`

evaluate the 'bin-by-bin'-central moment (around the mean value)

Parameters:

histo	histogram
order	the moment parameter
value	central value

Returns:: the evaluated central moment

Definition at line 119 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                        // RETURN
  if ( 0 == order ) { return 1.0   ; }                        // RETURN
  if ( 1 == order ) { return 0.0   ; }                        // RETURN
  if ( 2 == order ) 
  {
    const double sigma = histo->rms() ;
    return sigma * sigma ;                                    // RETURN
  }
  // delegate the actual evaluation to another method:
  return moment ( histo , order , mean ( histo ) ) ;
}

double Gaudi::Utils::HistoStats::centralMomentErr	(	const AIDA::IHistogram1D *	histo,
		const unsigned int	order
	)		`[static]`

evaluate the uncertanty for 'bin-by-bin'-central moment (around the mean value) ( the uncertanty is calculated with O(1/n2) precision)

Parameters:

histo	histogram
order	the moment parameter
value	central value

Returns:: the evaluated uncertanty in the central moment

Definition at line 144 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                    // RETURN
  const double n    = nEff ( histo ) ;
  if ( 0 >= n     ) { return 0.0   ; }                    // RETURN
  const double mu2  = centralMoment ( histo , 2             ) ; // mu(2)
  const double muo  = centralMoment ( histo ,     order     ) ; // mu(o)
  const double mu2o = centralMoment ( histo , 2 * order     ) ; // mu(2o)
  const double muom = centralMoment ( histo ,     order - 1 ) ; // mu(o-1)
  const double muop = centralMoment ( histo ,     order + 1 ) ; // mu(o+1)
  double result  =  mu2o  ;
  result        -=  2.0   * order * muom * muop ;
  result        -=  muo   * muo   ;
  result        +=  order * order * mu2  * muom * muom ;
  result        /=  n     ;
  result = std::max ( 0.0 , result ) ;
  return std:: sqrt ( result ) ;                            // RETURN
}

double Gaudi::Utils::HistoStats::kurtosis ( const AIDA::IHistogram1D * histo ) [static]

get the kurtosis for the histogram

Definition at line 192 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                    // RETURN 
  const double mu4 = centralMoment ( histo , 4 ) ;
  const double s4  = std::pow ( rms ( histo ) , 4 ) ;
  return ( std::fabs(s4)>0 ? mu4/s4 - 3.0 : 0.0 );
}

double Gaudi::Utils::HistoStats::kurtosisErr ( const AIDA::IHistogram1D * histo ) [static]

get the error in kurtosis for the histogram

Definition at line 203 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                    // RETURN 
  const double n = nEff ( histo ) ;
  if ( 3 > n      ) { return 0.0 ; }                      // RETURN   
  double result = 24 * n ;
  result *= ( n - 2 ) * ( n - 3 ) ;
  result /= ( n + 1 ) * ( n + 1 ) ;
  result /= ( n + 3 ) * ( n + 5 ) ;
  return std::sqrt ( result ) ;  
}

double Gaudi::Utils::HistoStats::mean ( const AIDA::IHistogram1D * histo ) [static]

get the mean value for the histogram (just for completeness)

Definition at line 227 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }
  return histo -> mean() ;    
}

double Gaudi::Utils::HistoStats::meanErr ( const AIDA::IHistogram1D * histo ) [static]

get an error in the mean value

Definition at line 236 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }
  const double n = nEff ( histo ) ;
  return 0 >= n ? 0.0 : rms ( histo ) / std::sqrt ( n ) ;
}

double Gaudi::Utils::HistoStats::moment	(	const AIDA::IHistogram1D *	histo,
		const unsigned int	order,
		const double	value = `0`
	)		`[static]`

get the "bin-by-bin"-moment around the specified "value"

Parameters:

histo	histogram
order	the moment parameter
value	central value

Returns:: the evaluated moment

Definition at line 49 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                       // RETURN
  if ( 0 == order ) { return 1.0   ; }                       // RETURN
  if ( 1 == order ) { return mean( histo ) - value ; }       // RETURN
  if ( 2 == order ) 
  {
    const double _r =         rms  ( histo ) ;
    const double _d = value - mean ( histo ) ;
    return _r *_r + _d * _d ;                            // RETURN
  }
  const double n = nEff ( histo )  ;
  if ( 0 >= n     ) { return 0.0   ; }                    // RETURN 
  
  const int _order = (int) order ;
  
  // get the exis 
  const AIDA::IAxis& axis = histo -> axis () ;
  // number of bins 
  const int nBins = axis.bins() ;
  double result = 0 ;
  double weight = 0 ;
  // loop over all bins 
  for ( int i = 0 ; i < nBins ; ++i ) 
  {
    const double lE   = axis . binLowerEdge ( i ) ;
    const double uE   = axis . binUpperEdge ( i ) ;
    //
    const double yBin = histo -> binHeight    ( i ) ;   // bin weight 
    const double xBin = 0.5 * ( lE + uE ) ;             // bin center 
    //
    weight += yBin ;
    result += yBin * std::pow ( xBin - value , _order ) ;
  }    
  if ( 0 != weight ) { result /= weight ; }
  return result ;
}

double Gaudi::Utils::HistoStats::momentErr	(	const AIDA::IHistogram1D *	histo,
		const unsigned int	order
	)		`[static]`

evaluate the uncertanty for 'bin-by-bin'-moment

Parameters:

histo	histogram
order	the moment parameter
value	central value

Returns:: the evaluated uncertanty in the moment

Definition at line 97 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                   // RETURN 
  const double n = nEff ( histo ) ;
  if ( 0 >= n     ) { return 0.0   ; }                   // RETURN
  const double a2o = moment ( histo , 2 * order ) ;      // a(2o)
  const double ao  = moment ( histo ,     order ) ;      // a(o) 
  double result = a2o - ao*ao ;
  result        /= n ;
  result = std::max ( 0.0 , result ) ;
  return std:: sqrt ( result ) ;                            // RETURN  
}

double Gaudi::Utils::HistoStats::nEff ( const AIDA::IHistogram1D * histo ) [static]

get the effective entries (just for completeness)

Definition at line 218 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }
  return histo -> equivalentBinEntries () ;
}

long Gaudi::Utils::HistoStats::nEntries	(	const AIDA::IHistogram1D *	histo,
		const int	imin,
		const int	imax
	)		`[static]`

get number of entries in histogram form the certain minimal bin up to the certain maximal bin (not-included)

Parameters:

histo	the pointer to the histogram
imin	the minimal bin number (included)
imax	the maximal bin number (not included)
number	of entries

Definition at line 491 of file HistoStats.cpp.

{
  if ( 0 == histo   ) { return s_long_bad ; }                         // RETURN 
  if ( imin == imax ) { return 0          ; }                         // RETURN 
  if ( imax < imin  ) { return nEntries  ( histo , imax ,imin ) ; }   // RETURN 
  //
  long result = 0 ;
  if ( 0 > imin  ) 
  { result += histo -> binEntries( AIDA::IAxis::UNDERFLOW_BIN )  ; }
  // get the exis 
  const AIDA::IAxis& axis = histo -> axis () ;
  // number of bins 
  const int nBins = axis.bins() ;
  if ( nBins  < imin ) { return 0 ; }                                 // RETURN 
  // loop over all bins 
  for ( int i = 0 ; i < nBins ; ++i ) 
  { if ( imin <= i && i < imax ) { result += histo->binEntries ( i ) ; } }
  //  
  if ( nBins  < imax )
  { result += histo -> binEntries( AIDA::IAxis::OVERFLOW_BIN ) ; }
  //
  return result ;                                                      // RETURN 
}

long Gaudi::Utils::HistoStats::nEntries	(	const AIDA::IHistogram1D *	histo,
		const int	imax
	)		`[static]`

get number of entries in histogram up to the certain bin (not-included)

Attention:: underflow bin is included!

Parameters:

histo	the pointer to the histogram
imax	the bin number (not included)
number	of entries

Definition at line 461 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_long_bad ; }                            // RETURN 
  if ( 0 > imax   ) { return 0          ; }                            // RETURN 
  long result = histo -> binEntries( AIDA::IAxis::UNDERFLOW_BIN )  ;
  
  // get the exis 
  const AIDA::IAxis& axis = histo -> axis () ;
  // number of bins 
  const int nBins = axis.bins() ;
  // loop over all bins 
  for ( int i = 0 ; i < nBins ; ++i ) 
  { if ( i < imax ) { result += histo->binEntries ( i ) ; } }
  // 
  if ( nBins  < imax )
  { result += histo -> binEntries( AIDA::IAxis::OVERFLOW_BIN ) ; }
  //
  return result ;
}

double Gaudi::Utils::HistoStats::nEntriesFrac	(	const AIDA::IHistogram1D *	histo,
		const int	imin,
		const int	imax
	)		`[static]`

get fraction of entries in histogram form the certain minimal bin up to the certain maximal bin (not-included)

Parameters:

histo	the pointer to the histogram
imin	the minimal bin number (included)
imax	the maximal bin number (not included)
fraction	of entries

Definition at line 549 of file HistoStats.cpp.

{
  if ( 0 == histo   ) { return s_bad ; }                              // RETURN
  const double N = histo->allEntries () ;
  if ( 0 >= N       ) { return s_bad ; }                              // RETURN 
  const long   n = nEntries ( histo , imin , imax ) ;
  if ( 0 >  n       ) { return s_bad ; }                              // RETURN 
  if ( n >  N       ) { return s_bad ; }                              // RETURN 
  //
  return n / N ;                                                      // REUTRN 
}

double Gaudi::Utils::HistoStats::nEntriesFrac	(	const AIDA::IHistogram1D *	histo,
		const int	imax
	)		`[static]`

get the fraction of entries in histogram up to the certain bin (not-included)

Attention:: underflow bin is included!

Parameters:

histo	the pointer to the histogram
imax	the bin number (not included)
fraction	of entries

Definition at line 526 of file HistoStats.cpp.

{
  if ( 0 == histo   ) { return s_bad ; }                              // RETURN
  //
  const double N = histo->allEntries () ;
  if ( 0 >= N       ) { return s_bad ; }                              // RETURN 
  const long   n = nEntries ( histo , imax ) ;
  if ( 0 >  n       ) { return s_bad ; }                              // RETURN 
  if ( n >  N       ) { return s_bad ; }                              // RETURN 
  //
  return n / N ;                                                      // REUTRN 
}

double Gaudi::Utils::HistoStats::nEntriesFracErr	(	const AIDA::IHistogram1D *	histo,
		const int	imin,
		const int	imax
	)		`[static]`

get the (binomial) error for the fraction of entries in histogram from the certain minimal bin up to the certain maximal bin (not-included)

Parameters:

histo	the pointer to the histogram
imin	the minimal bin number (included)
imax	the maximal bin number (not included)
error	for the fraction of entries

Definition at line 598 of file HistoStats.cpp.

{
  if ( 0 == histo   ) { return s_bad ; }                              // RETURN
  //
  const double N = histo->allEntries () ;
  if ( 0 >= N       ) { return s_bad ; }                              // RETURN 
  const long   n = nEntries ( histo , imin , imax ) ;
  if ( 0 >  n       ) { return s_bad ; }                              // RETURN 
  if ( n >  N       ) { return s_bad ; }                              // RETURN 
  //
  const double _n1 = std::max ( (double)       n   , 1.0 ) ;
  const double _n2 = std::max (          ( N - n ) , 1.0 ) ;
  //
  return std::sqrt ( _n1 * _n2 / N ) / N ;                             // RETURN 
}

double Gaudi::Utils::HistoStats::nEntriesFracErr	(	const AIDA::IHistogram1D *	histo,
		const int	imax
	)		`[static]`

get the (binominal) error for the fraction of entries in histogram up to the certain bin (not-included)

Attention:: underflow bin is included!

Parameters:

histo	the pointer to the histogram
imax	the bin number (not included)
error	for the fraction of entries

Definition at line 572 of file HistoStats.cpp.

{
  if ( 0 == histo   ) { return s_bad ; }                              // RETURN
  //
  const double N = histo->allEntries () ;
  if ( 0 >= N       ) { return s_bad ; }                              // RETURN 
  const long   n = nEntries ( histo , imax ) ;
  if ( 0 >  n       ) { return s_bad ; }                              // RETURN 
  if ( n >  N       ) { return s_bad ; }                              // RETURN 
  //
  const double _n1 = std::max ( (double)       n   , 1.0 ) ;
  const double _n2 = std::max (          ( N - n ) , 1.0 ) ;
  //
  return std::sqrt ( _n1 * _n2 / N ) / N ;                             // RETURN 
}

double Gaudi::Utils::HistoStats::overflowEntriesFrac ( const AIDA::IHistogram1D * histo ) [static]

the fraction of overflow entries (useful for shape comparison)

Definition at line 309 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                                // REUTRN  
  const long overflow = histo -> binEntries ( AIDA::IAxis::OVERFLOW_BIN )  ;
  if ( 0 == overflow ) { return 0 ; }                                 // REUTRN 
  const long all      = histo->allEntries() ;
  if ( 0 == all      ) { return 0 ; }                  // "CONVENTION?"  RETURN 
  if ( 0 >  all      ) { return s_bad ; }     // Lets be a bit paranoic, RETURN
  //
  double _tmp = (double) overflow ;
  _tmp /= all ;
  //
  return _tmp ;
}

double Gaudi::Utils::HistoStats::overflowEntriesFracErr ( const AIDA::IHistogram1D * histo ) [static]

error on fraction of overflow entries (useful for shape comparison)

Definition at line 373 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; } // RETURN 
  // 
  const double overflow = histo -> binEntries ( AIDA::IAxis::OVERFLOW_BIN );
  const double all      = histo -> allEntries () ;
  //
  if ( 0 > overflow || 0 >= all || overflow > all ) { return s_bad ; }
  // 
  const double n  = std::max ( overflow , 1.0 ) ;
  const double N  = all ;
  const double n1 = std::max ( N - n , 1.0 ) ;
  //
  return std::sqrt ( n * n1 / N ) / N ; // use the binomial formula 
}

double Gaudi::Utils::HistoStats::overflowIntegralFrac ( const AIDA::IHistogram1D * histo ) [static]

the fraction of overflow intergal (useful for shape comparison)

Definition at line 345 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                                // REUTRN  
  const double overflow = histo -> binHeight ( AIDA::IAxis::OVERFLOW_BIN )  ;
  if ( 0 == overflow ) { return 0 ; }                                 // REUTRN
  const double all      = histo -> sumAllBinHeights() ;
  if ( 0 == all      ) { return 0 ; }                  // "CONVENTION?"  RETURN 
  //
  return overflow / all ;
}

double Gaudi::Utils::HistoStats::overflowIntegralFracErr ( const AIDA::IHistogram1D * histo ) [static]

the error on fraction of overflow intergal

Definition at line 411 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                                // RETURN
  //
  const double all       = histo -> sumAllBinHeights () ;
  if ( 0 == all       ) { return s_bad ; }                            // RETURN 
  const double overflow  = histo -> binHeight ( AIDA::IAxis::OVERFLOW_BIN )  ;
  const double oErr      = histo -> binError  ( AIDA::IAxis::OVERFLOW_BIN )  ;
  if ( 0 > oErr       ) { return s_bad ; }                            // RETURN 
  const double aErr      = sumAllBinHeightErr ( histo ) ;
  if ( 0 > aErr       ) { return s_bad ; }                            // RETURN 
  //
  double error2  = oErr * oErr ;
  error2        += aErr * aErr * overflow * overflow / all / all ;
  error2        /=  all *  all ;
  
  return std::sqrt ( error2 ) ;
}

double Gaudi::Utils::HistoStats::rms ( const AIDA::IHistogram1D * histo ) [static]

get the rms value for the histogram (just for completeness)

Definition at line 246 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }
  return histo -> rms () ;    
}

double Gaudi::Utils::HistoStats::rmsErr ( const AIDA::IHistogram1D * histo ) [static]

get an error in the rms value

Definition at line 255 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }  
  const double n = nEff ( histo ) ;    
  if ( 1 >=  n ) { return 0.0 ; }
  double result = 2 + kurtosis ( histo ) ;
  result += 2.0 /( n - 1 ) ;
  result /= 4.0 * n ;
  result = std::max ( result , 0.0 ) ;
  return histo -> rms() * std::sqrt ( result ) ;
}

double Gaudi::Utils::HistoStats::skewness ( const AIDA::IHistogram1D * histo ) [static]

get the skewness for the histogram

Definition at line 167 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                      // RETURN
  const double mu3 = centralMoment ( histo , 3 ) ;
  const double s3  = std::pow ( rms ( histo ) , 3 ) ;
  return ( std::fabs(s3)>0 ? mu3/s3 : 0.0 );
}

double Gaudi::Utils::HistoStats::skewnessErr ( const AIDA::IHistogram1D * histo ) [static]

get the error in skewness for the histogram

Definition at line 178 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                     // RETURN 
  const double n = nEff ( histo ) ;
  if ( 2 > n      ) { return 0.0   ; }                     // RETURN
  double result = 6 ;
  result *= ( n - 2 )  ;
  result /= ( n + 1 ) * ( n + 3 ) ;    
  return std::sqrt ( result ) ;  
}

double Gaudi::Utils::HistoStats::sumAllBinHeightErr ( const AIDA::IHistogram1D * histo ) [static]

get an error in the sum of all bin height ("integral")

Definition at line 293 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }  
  //
  const double error = sumBinHeightErr( histo ) ;
  if ( 0 > error ) { return s_bad ; }
  const double err1 = histo->binError ( AIDA::IAxis::UNDERFLOW_BIN ) ;
  const double err2 = histo->binError ( AIDA::IAxis::OVERFLOW_BIN  ) ;
  //
  return std::sqrt ( error * error + err1 * err1 + err2 * err2 ) ;
}

double Gaudi::Utils::HistoStats::sumBinHeightErr ( const AIDA::IHistogram1D * histo ) [static]

get an error in the sum bin height ("in-range integral")

Definition at line 270 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }  
  //
  double error2 = 0 ;
  // get the exis 
  const AIDA::IAxis& axis = histo -> axis () ;
  // number of bins 
  const int nBins = axis.bins() ;
  // loop over all bins 
  for ( int i = 0 ; i < nBins ; ++i ) 
  {
    // get the error in each bin 
    const double berr = histo->binError ( i ) ;
    // accumulate the errors: 
    error2 += berr * berr ;    
  } 
  return std::sqrt ( error2 ) ;
}

double Gaudi::Utils::HistoStats::underflowEntriesFrac ( const AIDA::IHistogram1D * histo ) [static]

the fraction of underflow entries (useful for shape comparison)

Definition at line 327 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                                // REUTRN  
  const long underflow = histo -> binEntries ( AIDA::IAxis::UNDERFLOW_BIN )  ;
  if ( 0 == underflow ) { return 0 ; }                                // REUTRN 
  const long all      = histo->allEntries() ;
  if ( 0 == all      ) { return 0 ; }                  // "CONVENTION?"  RETURN 
  if ( 0 >  all      ) { return s_bad ; }     // Lets be a bit paranoic, RETURN
  //
  double _tmp = (double) underflow ;
  _tmp /= all ;
  //
  return _tmp ;
}

double Gaudi::Utils::HistoStats::underflowEntriesFracErr ( const AIDA::IHistogram1D * histo ) [static]

the error on fraction of underflow entries (useful for shape comparison)

Definition at line 392 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; } // RETURN 
  // 
  const double underflow = histo -> binEntries ( AIDA::IAxis::UNDERFLOW_BIN );
  const double all       = histo -> allEntries () ;
  //
  if ( 0 > underflow || 0 >= all || underflow > all ) { return s_bad ; }
  // 
  const double n  = std::max ( underflow , 1.0 ) ;
  const double N  = all ;
  const double n1 = std::max ( N - n , 1.0 ) ;
  //
  return std::sqrt ( n * n1 / N ) / N ; // use the binomial formula 
}

double Gaudi::Utils::HistoStats::underflowIntegralFrac ( const AIDA::IHistogram1D * histo ) [static]

the fraction of underflow integral (useful for shape comparison)

Definition at line 359 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                                // REUTRN  
  const double underflow = histo -> binHeight ( AIDA::IAxis::UNDERFLOW_BIN )  ;
  if ( 0 == underflow ) { return 0 ; }                                // REUTRN 
  const double all      = histo -> sumAllBinHeights() ;
  if ( 0 == all      ) { return 0 ; }                  // "CONVENTION?"  RETURN 
  //
  return underflow / all ; 
}

double Gaudi::Utils::HistoStats::underflowIntegralFracErr ( const AIDA::IHistogram1D * histo ) [static]

the error on fraction of underflow integral

Definition at line 433 of file HistoStats.cpp.

{
  if ( 0 == histo ) { return s_bad ; }                                // RETURN
  //
  const double all       = histo -> sumAllBinHeights () ;
  if ( 0 == all       ) { return s_bad ; }                            // RETURN 
  const double underflow  = histo -> binHeight ( AIDA::IAxis::UNDERFLOW_BIN )  ;
  const double oErr       = histo -> binError  ( AIDA::IAxis::UNDERFLOW_BIN )  ;
  if ( 0 > oErr       ) { return s_bad ; }                            // RETURN 
  const double aErr      = sumAllBinHeightErr ( histo ) ;
  if ( 0 > aErr       ) { return s_bad ; }                            // RETURN 
  //
  double error2  = oErr * oErr ;
  error2        += aErr * aErr * underflow * underflow / all / all ;
  error2        /=  all *  all ;
  //
  return std::sqrt ( error2 ) ;
}

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

/afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v23r2/GaudiUtils/GaudiUtils/HistoStats.h
/afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v23r2/GaudiUtils/src/Lib/HistoStats.cpp

Gaudi Framework, version v23r2

Gaudi::Utils::HistoStats Class Reference

Static Public Member Functions

Detailed Description

Member Function Documentation