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CmplxQRP.cc
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1997-03-07
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/*
Copyright (C) 1996 John W. Eaton
This file is part of Octave.
Octave 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, or (at your option) any
later version.
Octave 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 Octave; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#if defined (__GNUG__)
#pragma implementation
#endif
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <cassert>
#include "CmplxQRP.h"
#include "f77-fcn.h"
#include "lo-error.h"
#include "mx-inlines.cc"
extern "C"
{
int F77_FCN (zgeqpf, ZGEQPF) (const int&, const int&, Complex*,
const int&, int*, Complex*, Complex*,
double*, int&);
int F77_FCN (zungqr, ZUNGQR) (const int&, const int&, const int&,
Complex*, const int&, Complex*,
Complex*, const int&, int&);
}
// It would be best to share some of this code with ComplexQR class...
ComplexQRP::ComplexQRP (const ComplexMatrix& a, QR::type qr_type)
: ComplexQR (), p ()
{
init (a, qr_type);
}
void
ComplexQRP::init (const ComplexMatrix& a, QR::type qr_type)
{
assert (qr_type != QR::raw);
int m = a.rows ();
int n = a.cols ();
if (m == 0 || n == 0)
{
(*current_liboctave_error_handler)
("ComplexQR must have non-empty matrix");
return;
}
Array<Complex> tau (m < n ? m : n);
Complex *ptau = tau.fortran_vec ();
int lwork = 3*n > 32*m ? 3*n : 32*m;
Array<Complex> work (lwork);
Complex *pwork = work.fortran_vec ();
int info = 0;
ComplexMatrix A_fact = a;
if (m > n)
A_fact.resize (m, m, 0.0);
Complex *tmp_data = A_fact.fortran_vec ();
Array<double> rwork (2*n);
double *prwork = rwork.fortran_vec ();
Array<int> jpvt (n, 0);
int *pjpvt = jpvt.fortran_vec ();
// Code to enforce a certain permutation could go here...
F77_XFCN (zgeqpf, ZGEQPF, (m, n, tmp_data, m, pjpvt, ptau, pwork,
prwork, info));
if (f77_exception_encountered)
(*current_liboctave_error_handler) ("unrecoverable error in zgeqpf");
else
{
// Form Permutation matrix (if economy is requested, return the
// indices only!)
if (qr_type == QR::economy)
{
p.resize (1, n, 0.0);
for (int j = 0; j < n; j++)
p.elem (0, j) = jpvt.elem (j);
}
else
{
p.resize (n, n, 0.0);
for (int j = 0; j < n; j++)
p.elem (jpvt.elem (j) - 1, j) = 1.0;
}
if (qr_type == QR::economy && m > n)
r.resize (n, n, 0.0);
else
r.resize (m, n, 0.0);
int min_mn = m < n ? m : n;
for (int j = 0; j < n; j++)
{
int limit = j < min_mn-1 ? j : min_mn-1;
for (int i = 0; i <= limit; i++)
r.elem (i, j) = A_fact.elem (i, j);
}
int n2 = m;
if (qr_type == QR::economy)
n2 = min_mn;
F77_XFCN (zungqr, ZUNGQR, (m, n2, min_mn, tmp_data, m, ptau,
pwork, lwork, info));
if (f77_exception_encountered)
(*current_liboctave_error_handler) ("unrecoverable error in zungqr");
else
{
q = A_fact;
q.resize (m, n2);
}
}
}
/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/