STK::KmmBase< Derived > Class Template Reference

Base class for the Gaussian Kernel Mixture Models. More...

#include <STK_KmmBase.h>

Inheritance diagram for STK::KmmBase< Derived >:

Public Types
typedef IMixtureDensity< Derived >	Base
typedef hidden::MixtureTraits< Derived >::Array	Array
Public Types inherited from STK::IMixtureDensity< Derived >
typedef hidden::MixtureTraits< Derived >::Array	Array
typedef hidden::MixtureTraits< Derived >::Parameters	Parameters
typedef hidden::Traits< Array >::Type	Type

Public Member Functions
Real	sigma2 (int k) const
Real	dim (int k) const
Kernel::IKernel const *const	p_kernel () const
CArrayXX	dik () const
void	setDim (Real const &dim)
	set the dimensions of the kernel mixture model using an unique value
template<class Vector >
void	setDim (ExprBase< Vector > const &dim)
	set the dimension of the kernel mixture model
void	setKernel (Kernel::IKernel const *p_kernel)
	set the dimensions of the kernel mixture model using an unique value.
template<class Weights >
Real	impute (int i, int j, Weights const &pk) const
Real	rand (int i, int j, int k) const
template<class ArrayParam >
void	getParameters (ArrayParam &params) const
	This function is used in order to get the current values of the parameters in an array.
void	writeParameters (CArrayXX const *p_tik, ostream &os) const
	This function can be used to write summary of parameters to the output stream.
int	nbSample () const
int	nbCluster () const
Public Member Functions inherited from STK::IMixtureDensity< Derived >
	~IMixtureDensity ()
	destructor
int	nbCluster () const
int	nbSample () const
Real	lnNbSample () const
Array const *const &	p_data () const
Parameters const &	param () const
void	setData (Array const &data)
	Set the data set.
void	setData (Array const &data, int nbRow, int nbCol, bool byRow=true)
	Set the data set and give dimensions.
bool	initializeStep ()
	This function will be called at the beginning of the estimation process once the model is created and data is set.
void	setParametersStep ()
	set the parameters obtained with the intermediate results and release the intermediate results.
void	finalizeStep ()
	This function will be called once the model is estimated.
template<class Weights >
Type	sample (int i, int j, Weights const &tk) const
Public Member Functions inherited from STK::IRecursiveTemplate< Derived >
Derived &	asDerived ()
	static cast : return a reference of this with a cast to the derived class.
Derived const &	asDerived () const
	static cast : return a const reference of this with a cast to the derived class.
Derived *	asPtrDerived ()
	static cast : return a ptr on a Derived of this with a cast to the derived class.
Derived const *	asPtrDerived () const
	static cast : return a ptr on a constant Derived of this with a cast to the derived class.
Derived *	clone () const
	create a leaf using the copy constructor of the Derived class.
Derived *	clone (bool isRef) const
	create a leaf using the copy constructor of the Derived class and a flag determining if the clone is a reference or not.

Public Attributes
Parameters	param_
	parameters of the derived mixture model.

Protected Member Functions
	KmmBase (int nbCluster)
	default constructor
	KmmBase (KmmBase const &model)
	copy constructor
	~KmmBase ()
	destructor
void	initializeModel ()
	Initialize the model before its first use.
void	compute_dik (CArrayXX const *p_tik, CPointX const *p_tk)
	compute the distance of the ith individual to the kth centroid
void	initializeModelImpl ()
	default implementation of initializeModelImpl (do nothing)
Protected Member Functions inherited from STK::IMixtureDensity< Derived >
	IMixtureDensity (int nbCluster)
	Default constructor.
	IMixtureDensity (IMixtureDensity const &model)
	copy constructor.
void	initializeModel ()
	Initialize the model before its first use.
bool	initializeStepImpl ()
	default implementation of initializeStepImpl (do nothing and return true)
void	finalizeStepImpl ()
	default implementation of finalizeStepImpl (do nothing)
void	setNbSample (int nbSample)
	Set the number of sample of the model (needed by kernel models)
Protected Member Functions inherited from STK::IRecursiveTemplate< Derived >
	IRecursiveTemplate ()
	constructor.
	~IRecursiveTemplate ()
	destructor.

Protected Attributes
Kernel::IKernel const *	p_kernel_
	pointer on the kernel
CArrayXX	dik_
	Array of the intermediate results dik.
Protected Attributes inherited from STK::IMixtureDensity< Derived >
Parameters	param_
	parameters of the derived mixture model.

Private Member Functions
void	setData (Array const &data)
	Set the data set.

Detailed Description

template<class Derived>
class STK::KmmBase< Derived >

Base class for the Gaussian Kernel Mixture Models.

Definition at line 53 of file STK_KmmBase.h.

Member Typedef Documentation

Array

template<class Derived >

typedef hidden::MixtureTraits<Derived>::Array STK::KmmBase< Derived >::Array

Definition at line 57 of file STK_KmmBase.h.

Base

template<class Derived >

typedef IMixtureDensity<Derived > STK::KmmBase< Derived >::Base

Definition at line 56 of file STK_KmmBase.h.

Constructor & Destructor Documentation

KmmBase() [1/2]

template<class Derived >

STK::KmmBase< Derived >::KmmBase ( int  nbCluster )

inlineprotected

default constructor

Parameters

nbCluster

number of cluster in the model

Definition at line 67 of file STK_KmmBase.h.

: Base(nbCluster), p_kernel_(0) {}

KmmBase() [2/2]

template<class Derived >

STK::KmmBase< Derived >::KmmBase ( KmmBase< Derived > const &  model )

inlineprotected

copy constructor

Parameters

model

Model to copy

Definition at line 71 of file STK_KmmBase.h.

                      : Base(model)
                      , p_kernel_(model.p_kernel_)
                      , dik_(model.dik_)
    {}

~KmmBase()

template<class Derived >

STK::KmmBase< Derived >::~KmmBase ( )

inlineprotected

destructor

Definition at line 77 of file STK_KmmBase.h.

{}

Member Function Documentation

compute_dik()

template<class Derived >

void STK::KmmBase< Derived >::compute_dik ( CArrayXX const *  p_tik, CPointX const *  p_tk  )

protected

compute the distance of the ith individual to the kth centroid

using the kernel trick.

Definition at line 172 of file STK_KmmBase.h.

{
#ifdef STK_KERNELS_DEBUG
  stk_cout << _T("Entering KmmBase::compute_dik\n");
  stk_cout << _T("dik_.cols() =") << dik_.cols() << _T("\n");
  stk_cout << _T("dik_.rows() =") << dik_.rows() << _T("\n");
#endif
  CVectorX wik(dik_.rows());
  for (int k=dik_.beginCols(); k<dik_.endCols(); ++k)
  {
    // Compute wik=\sum_{j=1}^n k(x_i,x_j) t_{jk}/t_{.k}, for k=1,..,K
    for (int i= wik.begin(); i < wik.end(); ++i)
    {
      wik[i] = 0.;
      for (int j= wik.begin(); j < wik.end(); ++j)
      { wik[i] += p_kernel_->comp(i, j) * p_tik->elt(j,k);}
    }
    wik /= p_tk->elt(k);
    // compute dik_ = k(i,i) - 2 * wik + \sum_{i=1}^n t_{ik} w_{ik}/t_{.k}
    Real dk = p_tik->col(k).dot(wik)/p_tk->elt(k);
    for (int i= wik.begin(); i<wik.end(); ++i)
    { dik_(i,k) = p_kernel_->diag(i) - 2. * wik[i] + dk  ;}
  }
#ifdef STK_KERNELS_DEBUG
  stk_cout << _T("KmmBase::compute_dik done\n");
#endif
}

References _T, STK::ICArray< Derived >::col(), and stk_cout.

dik()

template<class Derived >

CArrayXX STK::KmmBase< Derived >::dik ( ) const

inline

Returns

distance of the individual to the kth centroid

Definition at line 88 of file STK_KmmBase.h.

{ return dik_;}

References STK::KmmBase< Derived >::dik_.

dim()

template<class Derived >

Real STK::KmmBase< Derived >::dim ( int  k ) const

inline

Returns

the value of dim in the kth

Definition at line 84 of file STK_KmmBase.h.

{ return param_.dim(k);}

References STK::KmmBase< Derived >::param_.

Referenced by STK::KmmBase< Derived >::setDim(), and STK::KmmBase< Derived >::setDim().

getParameters()

template<class Derived >

template<class ArrayParam >

void STK::KmmBase< Derived >::getParameters ( ArrayParam &  params ) const

inline

This function is used in order to get the current values of the parameters in an array.

Parameters

[out]

params

the array with the parameters of the mixture.

Definition at line 227 of file STK_KmmBase.h.

{
  param.resize(this->nbCluster(), 2);
  for (int k= param.beginRows(); k < param.endRows(); ++k)
  {
    param(k, baseIdx  ) = param_.sigma2(k);
    param(k, baseIdx+1) = param_.dim(k);
  }
}

References STK::baseIdx.

impute()

template<class Derived >

template<class Weights >

Real STK::KmmBase< Derived >::impute ( int  i, int  j, Weights const &  pk  ) const

inline

Returns

an imputation value for the jth variable of the ith sample

Parameters

i,j	indexes of the data to impute
pk	the probabilities of each class for the ith individual

Note

this method is not used as there is no missing values to impute

Definition at line 116 of file STK_KmmBase.h.

{ return 0.;}

initializeModel()

template<class Derived >

void STK::KmmBase< Derived >::initializeModel ( )

protected

Initialize the model before its first use.

This function is triggered when kernel is set. In this interface, the initializeModel() method

• set the number of samples and variables of the mixture model
• call the derived class implemented method

  initializeModelImpl()

  for initialization of the specific model parameters if needed.

Definition at line 211 of file STK_KmmBase.h.

{
  // set dimensions
  this->setNbSample(p_kernel_->nbSample());
  dik_.resize(p_kernel_->nbSample(), nbCluster());
  // call specific model initialization stuff (not really necessary)
  this->asDerived().initializeModelImpl();
  //compute_dik();
}

Referenced by STK::KmmBase< Derived >::setKernel().

initializeModelImpl()

template<class Derived >

void STK::KmmBase< Derived >::initializeModelImpl ( )

inlineprotected

default implementation of initializeModelImpl (do nothing)

Definition at line 157 of file STK_KmmBase.h.

{/* do nothing*/}

nbCluster()

template<class Derived >

int STK::IMixtureDensity< Derived >::nbCluster ( ) const

inline

Returns

the number of cluster

Definition at line 124 of file STK_IMixtureDensity.h.

{ return nbCluster_;}

nbSample()

template<class Derived >

int STK::IMixtureDensity< Derived >::nbSample ( ) const

inline

Returns

the total available observations

Definition at line 126 of file STK_IMixtureDensity.h.

{ return nbSample_;}

p_kernel()

template<class Derived >

Kernel::IKernel const *const STK::KmmBase< Derived >::p_kernel ( ) const

inline

Returns

the pointer on the kernel

Definition at line 86 of file STK_KmmBase.h.

{ return p_kernel_;}

References STK::KmmBase< Derived >::p_kernel_.

Referenced by STK::KmmBase< Derived >::setKernel().

rand()

template<class Derived >

Real STK::KmmBase< Derived >::rand ( int  i, int  j, int  k  ) const

inline

Returns

a simulated value for the jth variable of the ith sample

Note

this method is not used as there is no missing values to simulate

Definition at line 120 of file STK_KmmBase.h.

{ return 0.;}

setData()

template<class Derived >

void STK::KmmBase< Derived >::setData ( Array const &  data )

inlineprivate

Set the data set.

method is re-implemented for debug purpose

Parameters

data	the data set to set

Definition at line 164 of file STK_KmmBase.h.

{ this->p_dataij_ = 0;}

References STK::IMixtureDensity< Derived >::p_dataij_.

setDim() [1/2]

template<class Derived >

template<class Vector >

void STK::KmmBase< Derived >::setDim ( ExprBase< Vector > const &  dim )

inline

set the dimension of the kernel mixture model

Definition at line 95 of file STK_KmmBase.h.

    {
      STK_STATIC_ASSERT_ONE_DIMENSION_ONLY(Vector);
      param_.dim_ = dim.asDerived();
    }

References STK::KmmBase< Derived >::dim(), STK::KmmBase< Derived >::param_, and STK_STATIC_ASSERT_ONE_DIMENSION_ONLY.

setDim() [2/2]

template<class Derived >

void STK::KmmBase< Derived >::setDim ( Real const &  dim )

inline

set the dimensions of the kernel mixture model using an unique value

Definition at line 92 of file STK_KmmBase.h.

{ param_.dim_ = dim;}

References STK::KmmBase< Derived >::dim(), and STK::KmmBase< Derived >::param_.

setKernel()

template<class Derived >

void STK::KmmBase< Derived >::setKernel ( Kernel::IKernel const *  p_kernel )

inline

set the dimensions of the kernel mixture model using an unique value.

call to this method will triger the call to initializeModelImpl (as setData will not be called)

Definition at line 105 of file STK_KmmBase.h.

    {
      p_kernel_ = p_kernel;
      initializeModel();
    }

References STK::KmmBase< Derived >::initializeModel(), STK::KmmBase< Derived >::p_kernel(), and STK::KmmBase< Derived >::p_kernel_.

sigma2()

template<class Derived >

Real STK::KmmBase< Derived >::sigma2 ( int  k ) const

inline

Returns

the value of sigma2 in the kth cluster

Definition at line 82 of file STK_KmmBase.h.

{ return param_.sigma2(k);}

References STK::KmmBase< Derived >::param_.

writeParameters()

template<class Derived >

void STK::KmmBase< Derived >::writeParameters ( CArrayXX const *  p_tik, ostream &  os  ) const

inline

This function can be used to write summary of parameters to the output stream.

Parameters

p_tik	a constant pointer on the posterior probabilities
os	Stream where you want to write the summary of parameters.

Definition at line 241 of file STK_KmmBase.h.

{
  for (int k= p_tik->beginCols(); k < p_tik->endCols(); ++k)
  {
    os << _T("---> Component ") << k << _T("\n");
    os << _T("sigma2 = ") << param_.sigma2(k) << _T("\n");
    os << _T("dim = ")    << param_.dim(k)    << _T("\n");
  }
}

References _T.

Member Data Documentation

dik_

template<class Derived >

CArrayXX STK::KmmBase< Derived >::dik_

protected

Array of the intermediate results dik.

Definition at line 138 of file STK_KmmBase.h.

Referenced by STK::KmmBase< Derived >::dik().

p_kernel_

template<class Derived >

Kernel::IKernel const* STK::KmmBase< Derived >::p_kernel_

protected

pointer on the kernel

Definition at line 136 of file STK_KmmBase.h.

Referenced by STK::KmmBase< Derived >::p_kernel(), and STK::KmmBase< Derived >::setKernel().

param_

template<class Derived >

Parameters STK::IMixtureDensity< Derived >::param_

parameters of the derived mixture model.

Should be an instance of the STK::ModelParameters struct.

See also

STK::ModelParameters

Definition at line 180 of file STK_IMixtureDensity.h.

Referenced by STK::KmmBase< Derived >::dim(), STK::KmmBase< Derived >::setDim(), STK::KmmBase< Derived >::setDim(), and STK::KmmBase< Derived >::sigma2().

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

• STK_KmmBase.h