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itk::Statistics::ProbabilityDistribution Class Referenceabstract

#include <itkProbabilityDistribution.h>

+ Inheritance diagram for itk::Statistics::ProbabilityDistribution:
+ Collaboration diagram for itk::Statistics::ProbabilityDistribution:

Detailed Description

ProbabilityDistribution class defines common interface for statistical distributions (pdfs, cdfs, etc.).

ProbabilityDistribution defines a common interface for parameteric and non-parametric distributions. ProbabilityDistribution provides access to the probability density function (pdf), the cumulative distribution function (cdf), and the inverse cumulative distribution function.

ProbabilityDistribution also defines an abstract interface for setting parameters of distribution (mean/variance for a Gaussian, degrees of freedom for Student-t, etc.).

Note that nonparametric subclasses of ProbabilityDistribution are possible. For instance, a nonparametric implementation may use a histogram or kernel density function to model the distribution.

The EvaluatePDF(), EvaluateCDF, EvaluateInverseCDF() methods are all virtual, allowing algorithms to be written with an abstract interface to a distribution (with said distribution provided to the algorithm at run-time). Static methods, not requiring an instance of the distribution, are also allowed. The static methods allow for optimized access to distributions when the distribution is known a priori to the algorithm.

ProbabilityDistributions are univariate. Multivariate versions may be provided under a separate superclass (since the parameters to the pdf and cdf would have to be vectors not scalars). Perhaps this class will be named MultivariateProbabilityDistribution.

ProbabilityDistributions can be used for standard statistical tests: Z-scores, t-tests, chi-squared tests, F-tests, etc.

Note
This work is part of the National Alliance for Medical Image Computing (NAMIC), funded by the National Institutes of Health through the NIH Roadmap for Medical Research, Grant U54 EB005149. Information on the National Centers for Biomedical Computing can be obtained from http://commonfund.nih.gov/bioinformatics.

Definition at line 71 of file itkProbabilityDistribution.h.

Public Types

typedef SmartPointer< const SelfConstPointer
 
typedef Array< double > ParametersType
 
typedef SmartPointer< SelfPointer
 
typedef ProbabilityDistribution Self
 
typedef Object Superclass
 
- Public Types inherited from itk::Object
typedef SmartPointer< const SelfConstPointer
 
typedef SmartPointer< SelfPointer
 
typedef Object Self
 
typedef LightObject Superclass
 
- Public Types inherited from itk::LightObject
typedef SmartPointer< const SelfConstPointer
 
typedef SmartPointer< SelfPointer
 
typedef LightObject Self
 

Public Member Functions

virtual double EvaluateCDF (double x) const =0
 
virtual double EvaluateCDF (double x, const ParametersType &) const =0
 
virtual double EvaluateInverseCDF (double p) const =0
 
virtual double EvaluateInverseCDF (double p, const ParametersType &) const =0
 
virtual double EvaluatePDF (double x) const =0
 
virtual double EvaluatePDF (double x, const ParametersType &) const =0
 
virtual double GetMean () const =0
 
virtual const char * GetNameOfClass () const
 
virtual SizeValueType GetNumberOfParameters () const =0
 
virtual const ParametersTypeGetParameters ()
 
virtual double GetVariance () const =0
 
virtual bool HasMean () const =0
 
virtual bool HasVariance () const =0
 
virtual void SetParameters (const ParametersType &params)
 
- Public Member Functions inherited from itk::Object
unsigned long AddObserver (const EventObject &event, Command *)
 
unsigned long AddObserver (const EventObject &event, Command *) const
 
virtual LightObject::Pointer CreateAnother () const
 
virtual void DebugOff () const
 
virtual void DebugOn () const
 
CommandGetCommand (unsigned long tag)
 
bool GetDebug () const
 
MetaDataDictionaryGetMetaDataDictionary (void)
 
const MetaDataDictionaryGetMetaDataDictionary (void) const
 
virtual ModifiedTimeType GetMTime () const
 
virtual const TimeStampGetTimeStamp () const
 
bool HasObserver (const EventObject &event) const
 
void InvokeEvent (const EventObject &)
 
void InvokeEvent (const EventObject &) const
 
virtual void Modified () const
 
virtual void Register () const
 
void RemoveAllObservers ()
 
void RemoveObserver (unsigned long tag)
 
void SetDebug (bool debugFlag) const
 
void SetMetaDataDictionary (const MetaDataDictionary &rhs)
 
virtual void SetReferenceCount (int)
 
virtual void UnRegister () const
 
- Public Member Functions inherited from itk::LightObject
virtual void Delete ()
 
virtual int GetReferenceCount () const
 
 itkCloneMacro (Self)
 
void Print (std::ostream &os, Indent indent=0) const
 

Protected Member Functions

void PrintSelf (std::ostream &os, Indent indent) const
 
 ProbabilityDistribution (void)
 
virtual ~ProbabilityDistribution (void)
 
- Protected Member Functions inherited from itk::Object
 Object ()
 
bool PrintObservers (std::ostream &os, Indent indent) const
 
virtual void SetTimeStamp (const TimeStamp &time)
 
virtual ~Object ()
 
- Protected Member Functions inherited from itk::LightObject
virtual LightObject::Pointer InternalClone () const
 
 LightObject ()
 
virtual void PrintHeader (std::ostream &os, Indent indent) const
 
virtual void PrintTrailer (std::ostream &os, Indent indent) const
 
virtual ~LightObject ()
 

Protected Attributes

ParametersType m_Parameters
 

Private Member Functions

void operator= (const Self &)
 
 ProbabilityDistribution (const Self &)
 

Additional Inherited Members

- Static Public Member Functions inherited from itk::Object
static bool GetGlobalWarningDisplay ()
 
static void GlobalWarningDisplayOff ()
 
static void GlobalWarningDisplayOn ()
 
static Pointer New ()
 
static void SetGlobalWarningDisplay (bool flag)
 
- Protected Types inherited from itk::LightObject
typedef int InternalReferenceCountType
 

Member Typedef Documentation

Definition at line 79 of file itkProbabilityDistribution.h.

Type of the parameter vector.

Definition at line 82 of file itkProbabilityDistribution.h.

Definition at line 78 of file itkProbabilityDistribution.h.

Standard class typedefs

Definition at line 76 of file itkProbabilityDistribution.h.

Definition at line 77 of file itkProbabilityDistribution.h.

Constructor & Destructor Documentation

itk::Statistics::ProbabilityDistribution::ProbabilityDistribution ( void  )
inlineprotected

Definition at line 157 of file itkProbabilityDistribution.h.

virtual itk::Statistics::ProbabilityDistribution::~ProbabilityDistribution ( void  )
inlineprotectedvirtual

Definition at line 158 of file itkProbabilityDistribution.h.

itk::Statistics::ProbabilityDistribution::ProbabilityDistribution ( const Self )
private

Member Function Documentation

virtual double itk::Statistics::ProbabilityDistribution::EvaluateCDF ( double  x) const
pure virtual

Evaluate the cumulative distribution function (cdf). The parameters of the distribution are assigned via SetParameters(). See concrete subclasses for the ordering of parameters.

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::ChiSquareDistribution, and itk::Statistics::TDistribution.

virtual double itk::Statistics::ProbabilityDistribution::EvaluateCDF ( double  x,
const ParametersType  
) const
pure virtual

Evaluate the cumulative distribution function (cdf). The parameters for the distribution are passed as a parameters vector. See concrete subclasses for the ordering of parameters.

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::ChiSquareDistribution, and itk::Statistics::TDistribution.

virtual double itk::Statistics::ProbabilityDistribution::EvaluateInverseCDF ( double  p) const
pure virtual

Evaluate the inverse cumulative distribution function (inverse cdf). Parameter p must be between 0.0 and 1.0. The parameters of the distribution are assigned via SetParameters(). See concrete subclasses for the ordering of parameters.

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::ChiSquareDistribution, and itk::Statistics::TDistribution.

virtual double itk::Statistics::ProbabilityDistribution::EvaluateInverseCDF ( double  p,
const ParametersType  
) const
pure virtual

Evaluate the inverse cumulative distribution function (inverse cdf). Parameter p must be between 0.0 and 1.0. The parameters for the distribution are passed as a parameters vector. See concrete subclasses for the ordering of parameters.

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::ChiSquareDistribution, and itk::Statistics::TDistribution.

virtual double itk::Statistics::ProbabilityDistribution::EvaluatePDF ( double  x) const
pure virtual

Evaluate the probability density function (pdf). The parameters of the distribution are assigned via SetParameters().

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::ChiSquareDistribution, and itk::Statistics::TDistribution.

virtual double itk::Statistics::ProbabilityDistribution::EvaluatePDF ( double  x,
const ParametersType  
) const
pure virtual

Evaluate the probability density function (pdf). The parameters for the distribution are passed as a parameters vector. See concrete subclasses for the ordering of parameters.

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::ChiSquareDistribution, and itk::Statistics::TDistribution.

virtual double itk::Statistics::ProbabilityDistribution::GetMean ( ) const
pure virtual

Get the mean of the distribution. If the mean does not exist, then quiet_NaN may is returned.

Implemented in itk::Statistics::ChiSquareDistribution, itk::Statistics::TDistribution, and itk::Statistics::GaussianDistribution.

virtual const char* itk::Statistics::ProbabilityDistribution::GetNameOfClass ( ) const
virtual
virtual SizeValueType itk::Statistics::ProbabilityDistribution::GetNumberOfParameters ( ) const
pure virtual

Return the number of parameters that describe the distribution. For nonparametric distributions, this will be a function of the number of samples.

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::ChiSquareDistribution, and itk::Statistics::TDistribution.

virtual const ParametersType& itk::Statistics::ProbabilityDistribution::GetParameters ( )
virtual

Get the parameters of the distribution. See concrete subclasses for the order of parameters. Subclasses may provide convenience methods for setting parameters, i.e. SetDegreesOfFreedom(), etc.

virtual double itk::Statistics::ProbabilityDistribution::GetVariance ( ) const
pure virtual

Get the variance of the distribution. If the variance does not exist, then quiet_NaN is returned.

Implemented in itk::Statistics::GaussianDistribution, itk::Statistics::TDistribution, and itk::Statistics::ChiSquareDistribution.

virtual bool itk::Statistics::ProbabilityDistribution::HasMean ( ) const
pure virtual
virtual bool itk::Statistics::ProbabilityDistribution::HasVariance ( ) const
pure virtual
void itk::Statistics::ProbabilityDistribution::operator= ( const Self )
private
void itk::Statistics::ProbabilityDistribution::PrintSelf ( std::ostream &  os,
Indent  indent 
) const
inlineprotectedvirtual

Methods invoked by Print() to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from itk::Object.

Reimplemented in itk::Statistics::TDistribution.

Definition at line 159 of file itkProbabilityDistribution.h.

virtual void itk::Statistics::ProbabilityDistribution::SetParameters ( const ParametersType params)
inlinevirtual

Set the parameters of the distribution. See concrete subclasses for the order of the parameters. Subclasses may provide convenience methods for setting parameters, i.e. SetDegreesOfFreedom(), etc.

Definition at line 100 of file itkProbabilityDistribution.h.

References itk::Array< TValueType >::GetSize().

Member Data Documentation

ParametersType itk::Statistics::ProbabilityDistribution::m_Parameters
protected

Definition at line 165 of file itkProbabilityDistribution.h.


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