CMDS< ValueType > Class Template Reference

Classical Multidimensional Scaling (suited for small instances) More...

#include <CMDS.h>

Public Types
enum	DecompositionMethod { MethodQR, MethodCholesky, MethodLanczos }
typedef ublas::matrix< ValueType >	Matrix
typedef ublas::vector< ValueType >	Vector

Public Member Functions
	CMDS (Matrix &D, int method=(int) MethodQR)
	Perform classical multidimensional scaling. More...
const Vector &	getEigenvalues () const
void	project (int dim=2)
	Project referenced matrix D to dim dimensions. More...

Detailed Description

template<class ValueType>
class CMDS< ValueType >

Classical Multidimensional Scaling (suited for small instances)

Member Typedef Documentation

template<class ValueType>

typedef ublas::matrix<ValueType> CMDS< ValueType >::Matrix

template<class ValueType>

typedef ublas::vector<ValueType> CMDS< ValueType >::Vector

Member Enumeration Documentation

template<class ValueType>

enum CMDS::DecompositionMethod

Enumerator
MethodQR	complete eigendecomposition (infeasible for lager instances)
MethodCholesky	default method
MethodLanczos	if IETL is not available MethodCholesky is used instead

Constructor & Destructor Documentation

template<class ValueType>

CMDS< ValueType >::CMDS ( Matrix &  D, int  method = (int)MethodQR  )

inline

Perform classical multidimensional scaling.

Parameters

[in,out]

D

distance matrix, gets overwritten after CMDS!

Note

Input matrix will be destroyed!

As decomposition method one should choose MethodLanczos for larger matrices (requires IETL library!)

References ublasTools::double_center(), Cholesky< ValueType >::getL(), Eigenvalue< ValueType >::getRealEigenvalues(), Eigenvalue< ValueType >::getV(), CMDS< ValueType >::MethodCholesky, and CMDS< ValueType >::MethodLanczos.

Member Function Documentation

template<class ValueType>

const Vector& CMDS< ValueType >::getEigenvalues ( ) const

inline

Return real eigenvalues sorted from largest to smallest (empty when using Cholesky method!).

Returns

real eigenvalues sorted from largest to smallest

template<class ValueType>

void CMDS< ValueType >::project ( int  dim = 2 )

inline

Project referenced matrix D to dim dimensions.

References Lanczos< Matrix, Vector >::getEigenvalue(), Lanczos< Matrix, Vector >::getEigenvector(), CMDS< ValueType >::MethodLanczos, and CMDS< ValueType >::MethodQR.

Referenced by EventMap::create(), and FastMDS< ValueType >::FastMDS().