/** 
* @file EigValues.h
* @brief Computing eigenvalues and eigenvectors
* @author Michael Koch,Erik Rodner
* @date 08/19/2008

*/
#ifndef EigValuesINCLUDE
#define EigValuesINCLUDE

#include <vislearning/nice_nonvis.h>

#include "GenericMatrix.h"
  

namespace OBJREC {

/** Computing eigenvalues and eigenvectors */
class EigValues
{

    protected:
    
    public:
	
	/**
         * @param data matrix interface that does allow matrix-vector multiplications
         * @param k number of eigenvalues/eigenvectors
         * @param eigenvectors output Eigenvectors as Matrix
         * @param eigenvalues output Eigenvalues as Vector
         */
	virtual void getEigenvalues ( const GenericMatrix &data, NICE::Vector & eigenvalues, NICE::Matrix & eigenvectors, uint k ) = 0;

	virtual ~EigValues() {};

};

#ifdef USE_BROKEN_LANCZOS
/** BROKEN: lanczos iteration */
class EVLanczos : public EigValues
{
    protected:
	uint maxiterations;
	double mindelta;

    public:
	EVLanczos ( uint _maxiterations = 100, double _mindelta = 0.01 ) 
	    : maxiterations(_maxiterations), mindelta(_mindelta) {};


	/**
         * Lanczos Iteration, to get k first eigenvectors and eigenvalues
         * @param data matrix interface that does allow matrix-vector multiplications
         * @param k number of eigenvalues/eigenvectors
         * @param eigenvectors output Eigenvectors as Matrix
         * @param eigenvalues output Eigenvalues as Vector
         */
	// refactor-nice.pl: check this substitution
	// old: void getEigenvalues ( const GenericMatrix &data, Vector & eigenvalues, Matrix & eigenvectors, uint k );	
	void getEigenvalues ( const GenericMatrix &data, NICE::Vector & eigenvalues, NICE::Matrix & eigenvectors, uint k );	
};
#endif

/** arnoldi iteration */
class EVArnoldi : public EigValues
{
    protected:
	uint maxiterations;
	double mindelta;

    public:
	EVArnoldi ( uint _maxiterations = 100, double _mindelta = 0.01 ) 
	    : maxiterations(_maxiterations), mindelta(_mindelta) {};

	/**
         * Arnoldi Iteration, to get k first eigenvectors and eigenvalues
         * @param data matrix interface that does allow matrix-vector multiplications
         * @param k number of eigenvalues/eigenvectors
         * @param eigenvectors output Eigenvectors as Matrix
         * @param eigenvalues output Eigenvalues as Vector
         */
	// refactor-nice.pl: check this substitution
	// old: void getEigenvalues ( const GenericMatrix &data, Vector & eigenvalues, Matrix & eigenvectors, uint k );	
	void getEigenvalues ( const GenericMatrix &data, NICE::Vector & eigenvalues, NICE::Matrix & eigenvectors, uint k );	
};


} // namespace

#endif