Mercurial > octave
view libinterp/corefcn/hess.cc @ 20939:b17fda023ca6
maint: Use new C++ archetype in more files.
Place input validation first in files.
Move declaration of retval down in function to be closer to point of usage.
Eliminate else clause after if () error.
Use "return ovl()" where it makes sense.
* find.cc, gammainc.cc, gcd.cc, getgrent.cc, getpwent.cc, givens.cc,
graphics.cc, help.cc, hess.cc, hex2num.cc, input.cc, kron.cc, load-path.cc,
load-save.cc, lookup.cc, mappers.cc, matrix_type.cc, mgorth.cc, nproc.cc,
ordschur.cc, pager.cc, pinv.cc, pr-output.cc, profiler.cc, psi.cc, quad.cc,
rcond.cc, regexp.cc, schur.cc, sighandlers.cc, sparse.cc, str2double.cc,
strfind.cc, strfns.cc, sub2ind.cc, svd.cc, sylvester.cc, symtab.cc,
syscalls.cc, sysdep.cc, time.cc, toplev.cc, tril.cc, tsearch.cc, typecast.cc,
urlwrite.cc, utils.cc, variables.cc, __delaunayn__.cc, __eigs__.cc,
__glpk__.cc, __magick_read__.cc, __osmesa_print__.cc, __voronoi__.cc, amd.cc,
audiodevinfo.cc, audioread.cc, chol.cc, colamd.cc, dmperm.cc, fftw.cc, qr.cc,
symbfact.cc, symrcm.cc, ov-bool-mat.cc, ov-cell.cc, ov-class.cc,
ov-classdef.cc, ov-fcn-handle.cc, ov-fcn-inline.cc, ov-flt-re-mat.cc,
ov-java.cc, ov-null-mat.cc, ov-oncleanup.cc, ov-re-mat.cc, ov-struct.cc,
ov-typeinfo.cc, ov-usr-fcn.cc, ov.cc, octave.cc:
Use new C++ archetype in more files.
author | Rik <rik@octave.org> |
---|---|
date | Fri, 18 Dec 2015 15:37:22 -0800 |
parents | 03e4ddd49396 |
children | 48b2ad5ee801 |
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/* Copyright (C) 1996-2015 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "CmplxHESS.h" #include "dbleHESS.h" #include "fCmplxHESS.h" #include "floatHESS.h" #include "defun.h" #include "error.h" #include "gripes.h" #include "oct-obj.h" #include "utils.h" DEFUN (hess, args, nargout, "-*- texinfo -*-\n\ @deftypefn {} {@var{H} =} hess (@var{A})\n\ @deftypefnx {} {[@var{P}, @var{H}] =} hess (@var{A})\n\ @cindex Hessenberg decomposition\n\ Compute the Hessenberg decomposition of the matrix @var{A}.\n\ \n\ The Hessenberg decomposition is\n\ @tex\n\ $$\n\ A = PHP^T\n\ $$\n\ where $P$ is a square unitary matrix ($P^TP = I$), and $H$\n\ is upper Hessenberg ($H_{i,j} = 0, \\forall i > j+1$).\n\ @end tex\n\ @ifnottex\n\ @code{@var{P} * @var{H} * @var{P}' = @var{A}} where @var{P} is a square\n\ unitary matrix (@code{@var{P}' * @var{P} = I}, using complex-conjugate\n\ transposition) and @var{H} is upper Hessenberg\n\ (@code{@var{H}(i, j) = 0 forall i > j+1)}.\n\ @end ifnottex\n\ \n\ The Hessenberg decomposition is usually used as the first step in an\n\ eigenvalue computation, but has other applications as well\n\ (see @nospell{Golub, Nash, and Van Loan},\n\ IEEE Transactions on Automatic Control, 1979).\n\ @seealso{eig, chol, lu, qr, qz, schur, svd}\n\ @end deftypefn") { if (args.length () != 1) print_usage (); octave_value arg = args(0); octave_idx_type nr = arg.rows (); octave_idx_type nc = arg.columns (); int arg_is_empty = empty_arg ("hess", nr, nc); if (arg_is_empty < 0) return octave_value_list (); else if (arg_is_empty > 0) return octave_value_list (2, Matrix ()); if (nr != nc) { gripe_square_matrix_required ("hess"); return octave_value_list (); } octave_value_list retval; if (arg.is_single_type ()) { if (arg.is_real_type ()) { FloatMatrix tmp = arg.float_matrix_value (); FloatHESS result (tmp); if (nargout <= 1) retval = ovl (result.hess_matrix ()); else retval = ovl (result.unitary_hess_matrix (), result.hess_matrix ()); } else if (arg.is_complex_type ()) { FloatComplexMatrix ctmp = arg.float_complex_matrix_value (); FloatComplexHESS result (ctmp); if (nargout <= 1) retval = ovl (result.hess_matrix ()); else retval = ovl (result.unitary_hess_matrix (), result.hess_matrix ()); } } else { if (arg.is_real_type ()) { Matrix tmp = arg.matrix_value (); HESS result (tmp); if (nargout <= 1) retval = ovl (result.hess_matrix ()); else retval = ovl (result.unitary_hess_matrix (), result.hess_matrix ()); } else if (arg.is_complex_type ()) { ComplexMatrix ctmp = arg.complex_matrix_value (); ComplexHESS result (ctmp); if (nargout <= 1) retval = ovl (result.hess_matrix ()); else retval = ovl (result.unitary_hess_matrix (), result.hess_matrix ()); } else { gripe_wrong_type_arg ("hess", arg); } } return retval; } /* %!test %! a = [1, 2, 3; 5, 4, 6; 8, 7, 9]; %! [p, h] = hess (a); %! assert (p * h * p', a, sqrt (eps)); %!test %! a = single ([1, 2, 3; 5, 4, 6; 8, 7, 9]); %! [p, h] = hess (a); %! assert (p * h * p', a, sqrt (eps ("single"))); %!error hess () %!error hess ([1, 2; 3, 4], 2) %!error <argument must be a square matrix> hess ([1, 2; 3, 4; 5, 6]) */