TUnuranMultiContDist Class Reference

#include <TUnuranMultiContDist.h>

Inheritance diagram for TUnuranMultiContDist:


Public Member Functions
	TUnuranMultiContDist (TF1 *func=0, unsigned int dim=0, bool isLogPdf=false)
	TUnuranMultiContDist (const ROOT::Math::IMultiGenFunction &pdf, bool isLogPdf=false)
virtual	~TUnuranMultiContDist ()
	TUnuranMultiContDist (const TUnuranMultiContDist &)
TUnuranMultiContDist &	operator= (const TUnuranMultiContDist &rhs)
virtual TUnuranMultiContDist *	Clone () const
unsigned int	NDim () const
void	SetDomain (const double xmin, const double xmax)
void	SetMode (const double *x)
const double *	GetLowerDomain () const
const double *	GetUpperDomain () const
const double *	GetMode () const
bool	IsLogPdf () const
double	Pdf (const double *x) const
void	Gradient (const double x, double grad) const
double	Derivative (const double *x, int icoord) const
Private Attributes
const ROOT::Math::IMultiGenFunction *	fPdf
std::vector< double >	fXmin
std::vector< double >	fXmax
std::vector< double >	fMode
bool	fIsLogPdf
bool	fOwnFunc

Detailed Description

TUnuranMultiContDist class describing multi dimensional continuous distributions. It is used by TUnuran to generate a set of random numbers according to this distribution via TUnuran::Sample(double *). The class can be constructed from a multi-dimensional function (TF1 pointer, which can be actually also a TF2 or a TF3). It provides a method to set the domain of the distribution ( SetDomain ) which will correspond to the range of the generated random numbers. By default the domain is [(-inf,-inf,...)(+inf,+inf,...)], indipendently of the range set in the TF1 class used to construct the distribution.

The derivatives of the pdf which are used by some UNURAN methods are estimated numerically in the Derivative() method. Some extra information (like distribution mode) can be set using SetMode. Some methods require instead of the pdf the log of the pdf. This can also be controlled by setting a flag when constructing this class.

Definition at line 49 of file TUnuranMultiContDist.h.

Constructor & Destructor Documentation

TUnuranMultiContDist::TUnuranMultiContDist	(	TF1 *	func = `0`,
		unsigned int	dim = `0`,
		bool	isLogPdf = `false`
	)

Constructor from a TF1 object representing the Probability density function. The derivatives of the Pdf are estimated, when required by the UNURAN algorithm, using numerical derivation. If a value of dim 0 is passed , the dimension of the function is taken from TF1::GetNdim(). This works only for 2D and 3D (for TF2 and TF3 objects).

Definition at line 29 of file TUnuranMultiContDist.cxx.

Referenced by Clone().

TUnuranMultiContDist::TUnuranMultiContDist	(	const ROOT::Math::IMultiGenFunction &	pdf,
		bool	isLogPdf = `false`
	)

Constructor as before but from a generic function object interface for multi-dim functions

Definition at line 20 of file TUnuranMultiContDist.cxx.

TUnuranMultiContDist::~TUnuranMultiContDist ( ) [virtual]

Destructor

Definition at line 65 of file TUnuranMultiContDist.cxx.

References fOwnFunc, and fPdf.

TUnuranMultiContDist::TUnuranMultiContDist ( const TUnuranMultiContDist & )

Copy constructor

Definition at line 39 of file TUnuranMultiContDist.cxx.

References operator=().

Member Function Documentation

TUnuranMultiContDist & TUnuranMultiContDist::operator= ( const TUnuranMultiContDist & rhs )

Assignment operator

Definition at line 47 of file TUnuranMultiContDist.cxx.

References ROOT::Math::IBaseFunctionMultiDim::Clone(), fIsLogPdf, fMode, fOwnFunc, fPdf, fXmax, and fXmin.

Referenced by TUnuranMultiContDist().

virtual TUnuranMultiContDist* TUnuranMultiContDist::Clone ( ) const [inline, virtual]

Clone (required by base class)

Implements TUnuranBaseDist.

Definition at line 88 of file TUnuranMultiContDist.h.

References TUnuranMultiContDist().

unsigned int TUnuranMultiContDist::NDim ( ) const [inline]

get number of dimension of the distribution

Definition at line 94 of file TUnuranMultiContDist.h.

References fPdf, and ROOT::Math::IBaseFunctionMultiDim::NDim().

Referenced by Derivative(), Gradient(), SetDomain(), and SetMode().

void TUnuranMultiContDist::SetDomain	(	const double *	xmin,
		const double *	xmax
	)			`[inline]`

set the domain of the distribution giving an array of minimum and maximum values By default otherwise the domain is undefined, i.e. is [-inf,+inf] To remove the domain do a SetDomain(0,0). There is no possibility to have a domain defined in only one coordinate. Use instead inf or DOUBLE_MAX to specify un infinite domain in that coordinate

Definition at line 105 of file TUnuranMultiContDist.h.

References fXmax, fXmin, and NDim().

Referenced by unuranMulti2D(), and unuranMultiDim().

void TUnuranMultiContDist::SetMode ( const double * x ) [inline]

set the mode of the distribution (coordinates of the distribution maximum values)

Definition at line 114 of file TUnuranMultiContDist.h.

References fMode, and NDim().

Referenced by unuranMulti2D(), and unuranMultiDim().

const double* TUnuranMultiContDist::GetLowerDomain ( ) const [inline]

get the distribution lower domain values. Return a null pointer if domain is not defined

Definition at line 121 of file TUnuranMultiContDist.h.

References fXmax, and fXmin.