/** 
* @file GenericMatrix.h
* @brief matrix interface for indirect matrix multiplications
* @author Erik Rodner
* @date 05/14/2009

*/
#ifndef GENERICMATRIXINCLUDE
#define GENERICMATRIXINCLUDE

#include "core/basics/triplet.h"
#include "AlgebraTools.h"
#include "core/vector/SparseVector.h"
  

namespace OBJREC {

/** matrix interface for indirect matrix multiplications */
class GenericMatrix
{

    protected:

    public:

	/** multiply with a vector: A*x = y */
	virtual void multiply ( NICE::Vector & y, const NICE::Vector & x ) const  = 0;

	/** get the number of rows in A */
	virtual uint rows() const = 0;

	/** get the number of columns in A */
	virtual uint cols() const = 0;

	/** simple destructor */
	virtual ~GenericMatrix() {};
     
};

class GMSlowICE : public GenericMatrix
{
    protected:
	NICE::Matrix A;

    public:
	GMSlowICE ( const NICE::Matrix & _A ) : A(_A) {};
    
	/** get the number of rows in A */
	uint rows() const { return A.rows(); };

	/** get the number of columns in A */
	uint cols() const { return A.cols(); };

	/** multiply with a vector: A*x = y */
	void multiply ( NICE::Vector & y, const NICE::Vector & x ) const
	{ y.multiply ( A, x ); };

};

class GMSparse : public GenericMatrix
{
    protected:
	std::vector< NICE::triplet<int, int, double> > A;
	uint m_rows;
	uint m_cols;

    public:
	GMSparse ( uint _rows, uint _cols ) : m_rows(_rows), m_cols(_cols) {}
	GMSparse ( const NICE::Matrix & A, double epsilon = 1e-9 );

	/** get the number of rows in A */
	uint rows() const { return m_rows; };

	/** get the number of columns in A */
	uint cols() const { return m_cols; };

	/** multiply with a vector: A*x = y */
	void multiply ( NICE::Vector & y, const NICE::Vector & x ) const;

};

class GMCovariance : public GenericMatrix
{
    protected:
	const NICE::Matrix *data;
	uint m_rows;
	uint m_cols;

    public:
	GMCovariance ( const NICE::Matrix *data );

	/** get the number of rows in A */
	uint rows() const { return m_rows; };

	/** get the number of columns in A */
	uint cols() const { return m_cols; };

	/** multiply with a vector: A*x = y */
	void multiply ( NICE::Vector & y, const NICE::Vector & x ) const;

};



} // namespace

#endif