qccmatrixsvd.3

spiht for linux this is used to decod and encode vedio i wich all enjoy

.TH QCCMATRIXSVD 3 "QCCPACK" ""
.SH NAME
QccMatrixSVD
\- singular value decomposition
.SH SYNOPSIS
.B #include "libQccPack.h"
.sp
.BI "int QccMatrixSVD(const QccMatrix " A ", int " num_rows ", int " num_cols ", QccMatrix " U ", QccVector " S ", QccMatrix " V );
.SH DESCRIPTION
.B QccMatrixSVD()
performs the singular value decomposition (SVD) of matrix
.IR A
which has size
.I num_rows
x
.IR num_cols .
The SVD is returned in the form of matrix
.IR U
(size
.IR num_rows
x
.IR num_cols ),
vector
.IR S
(length
.IR num_cols ),
and matrix
.IR V
(size
.IR num_cols
x
.IR num_cols ),
such that
.IR A
=
.IR U
*
.RI diag( S )
*
.IR V ^T,
where
.RI diag( S )
is the
.IR num_cols
x
.IR num_cols
matrix with
.I S
on the diagonal.
.LP
Any of
.IR U ,
.IR V ,
or
.IR S
can be
.BR NULL ,
in which case the corresponding value is calculated but not returned.
.SH "IMPLEMENTATION"
The QccPack implementation of SVD is essentially a call to
.BR gsl_linalg_SV_decomp (3),
part of the GNU Scientific Library (GSL). As a consequence, if GSL
is not available,
.BR QccMatrixSVD()
will not work.
In the case that
.IR num_rows
is less than
.IR num_cols ,
.BR gsl_linalg_SV_decomp (3)
cannot be employed directly. In this case,
.IR num_cols " - " num_rows
rows of zeros are concatenated onto
.IR A
before calling
.BR gsl_linalg_SV_decomp (3) ,
and the output quantities
.SH "SEE ALSO"
.BR gsl_linalg_SV_decomp (3),
.BR QccMatrix (3),
.BR QccPack (3)
.SH AUTHOR
Copyright (C) 1997-2009  James E. Fowler
.\"  The programs herein are free software; you can redistribute them an.or
.\"  modify them 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.
.\"  
.\"  These programs are distributed in the hope that they 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 these programs; if not, write to the Free Software
.\"  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.