/***
 **     libface - Library of face recognition and supporting algorithms
        Copyright (c) 2003 Stefan Farthofer

	This file is part of libface, which is

        free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 2 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

	For further information seek us at http://sourceforge.net/projects/openbio/
**	or write an email to dimitri.pissarenko@gmx.net or farthofer@chello.at.
***/

/* matrix calculation functions */
/* S means symmetric
 * Q means square
 * D means distinct source and destination, if not specified the first operand will be replaced
 *   with the result
 */

#ifndef __MATRIX_H
#define __MATRIX_H


//these are used by computeEgenVectorValue, which was copied from
//Turk&Pentland (they got it from numerical recipes in C)
#define EPS 0.000000001f
#define ROTATE(a, i, j, k, l, n) g=a[i*n+j]; h=a[k*n+l]; a[i*n+j] = g-s*(h+g*tau); \
  a[k*n+l] = h+s*(g-h*tau)


void _matTransposeD(float* dst, float* src, unsigned int rows, unsigned int cols);
void _matTransposeQ(float* mat, unsigned int n);

/* computes m x n * n x p matrix multiply */
void _matMultiplyD(float* dst, float* a, float* b, unsigned int m, unsigned int n, unsigned int p);

/* subtract same-sized matrizes */
void _matSubtractD(float* dst, float* a, float* b, unsigned int m, unsigned int n);

/* add same-sized matrizes */
void _matAdd(float* dst, float* b, unsigned int m, unsigned int n);

/* computes eigenvalues and vectors of a symmetric matrix 
 * columns of matVectors contain the eigenvectors
 */
int _matEigenSD(float* mat, int n, float* vecValues, float* matVectors);

#endif /* header guard */