Mercurial > octave-nkf
view libinterp/corefcn/schur.cc @ 17787:175b392e91fe
Use GNU style coding conventions for code in libinterp/
* libinterp/corefcn/Cell.h, libinterp/corefcn/__contourc__.cc,
libinterp/corefcn/__dispatch__.cc, libinterp/corefcn/__lin_interpn__.cc,
libinterp/corefcn/__pchip_deriv__.cc, libinterp/corefcn/__qp__.cc,
libinterp/corefcn/balance.cc, libinterp/corefcn/besselj.cc,
libinterp/corefcn/betainc.cc, libinterp/corefcn/bitfcns.cc,
libinterp/corefcn/bsxfun.cc, libinterp/corefcn/c-file-ptr-stream.cc,
libinterp/corefcn/c-file-ptr-stream.h, libinterp/corefcn/cellfun.cc,
libinterp/corefcn/colloc.cc, libinterp/corefcn/comment-list.h,
libinterp/corefcn/conv2.cc, libinterp/corefcn/daspk.cc,
libinterp/corefcn/dasrt.cc, libinterp/corefcn/dassl.cc,
libinterp/corefcn/data.cc, libinterp/corefcn/debug.cc,
libinterp/corefcn/defaults.cc, libinterp/corefcn/defaults.in.h,
libinterp/corefcn/defun-int.h, libinterp/corefcn/defun.cc,
libinterp/corefcn/det.cc, libinterp/corefcn/dirfns.cc,
libinterp/corefcn/display.cc, libinterp/corefcn/dlmread.cc,
libinterp/corefcn/dot.cc, libinterp/corefcn/dynamic-ld.cc,
libinterp/corefcn/dynamic-ld.h, libinterp/corefcn/eig.cc,
libinterp/corefcn/ellipj.cc, libinterp/corefcn/error.cc,
libinterp/corefcn/error.h, libinterp/corefcn/event-queue.h,
libinterp/corefcn/fft.cc, libinterp/corefcn/fft2.cc, libinterp/corefcn/fftn.cc,
libinterp/corefcn/file-io.cc, libinterp/corefcn/filter.cc,
libinterp/corefcn/find.cc, libinterp/corefcn/gammainc.cc,
libinterp/corefcn/gcd.cc, libinterp/corefcn/getgrent.cc,
libinterp/corefcn/getpwent.cc, libinterp/corefcn/getrusage.cc,
libinterp/corefcn/givens.cc, libinterp/corefcn/gl-render.cc,
libinterp/corefcn/gl2ps-renderer.cc, libinterp/corefcn/gl2ps-renderer.h,
libinterp/corefcn/graphics.cc, libinterp/corefcn/graphics.in.h,
libinterp/corefcn/gripes.cc, libinterp/corefcn/gripes.h,
libinterp/corefcn/help.cc, libinterp/corefcn/hess.cc,
libinterp/corefcn/hex2num.cc, libinterp/corefcn/input.cc,
libinterp/corefcn/input.h, libinterp/corefcn/inv.cc,
libinterp/corefcn/jit-ir.h, libinterp/corefcn/jit-typeinfo.cc,
libinterp/corefcn/jit-typeinfo.h, libinterp/corefcn/jit-util.h,
libinterp/corefcn/kron.cc, libinterp/corefcn/load-path.cc,
libinterp/corefcn/load-path.h, libinterp/corefcn/load-save.cc,
libinterp/corefcn/load-save.h, libinterp/corefcn/lookup.cc,
libinterp/corefcn/ls-ascii-helper.cc, libinterp/corefcn/ls-hdf5.cc,
libinterp/corefcn/ls-hdf5.h, libinterp/corefcn/ls-mat-ascii.cc,
libinterp/corefcn/ls-mat-ascii.h, libinterp/corefcn/ls-mat4.cc,
libinterp/corefcn/ls-mat5.cc, libinterp/corefcn/ls-mat5.h,
libinterp/corefcn/ls-oct-ascii.cc, libinterp/corefcn/lsode.cc,
libinterp/corefcn/lu.cc, libinterp/corefcn/luinc.cc,
libinterp/corefcn/mappers.cc, libinterp/corefcn/matrix_type.cc,
libinterp/corefcn/max.cc, libinterp/corefcn/md5sum.cc,
libinterp/corefcn/mex.cc, libinterp/corefcn/mexproto.h,
libinterp/corefcn/mgorth.cc, libinterp/corefcn/mxarray.in.h,
libinterp/corefcn/nproc.cc, libinterp/corefcn/oct-hist.cc,
libinterp/corefcn/oct-lvalue.h, libinterp/corefcn/oct-map.cc,
libinterp/corefcn/oct-map.h, libinterp/corefcn/oct-obj.h,
libinterp/corefcn/oct-prcstrm.h, libinterp/corefcn/oct-stdstrm.h,
libinterp/corefcn/oct-stream.cc, libinterp/corefcn/oct-stream.h,
libinterp/corefcn/octave-link.cc, libinterp/corefcn/octave-link.h,
libinterp/corefcn/pager.cc, libinterp/corefcn/pinv.cc,
libinterp/corefcn/pr-output.cc, libinterp/corefcn/procstream.h,
libinterp/corefcn/profiler.cc, libinterp/corefcn/pt-jit.cc,
libinterp/corefcn/pt-jit.h, libinterp/corefcn/quad.cc,
libinterp/corefcn/quadcc.cc, libinterp/corefcn/qz.cc,
libinterp/corefcn/rand.cc, libinterp/corefcn/rcond.cc,
libinterp/corefcn/regexp.cc, libinterp/corefcn/schur.cc,
libinterp/corefcn/sighandlers.cc, libinterp/corefcn/sighandlers.h,
libinterp/corefcn/sparse-xdiv.cc, libinterp/corefcn/sparse-xdiv.h,
libinterp/corefcn/sparse-xpow.cc, libinterp/corefcn/sparse.cc,
libinterp/corefcn/spparms.cc, libinterp/corefcn/sqrtm.cc,
libinterp/corefcn/str2double.cc, libinterp/corefcn/strfind.cc,
libinterp/corefcn/strfns.cc, libinterp/corefcn/sub2ind.cc,
libinterp/corefcn/svd.cc, libinterp/corefcn/syl.cc,
libinterp/corefcn/symtab.cc, libinterp/corefcn/symtab.h,
libinterp/corefcn/syscalls.cc, libinterp/corefcn/sysdep.cc,
libinterp/corefcn/sysdep.h, libinterp/corefcn/time.cc,
libinterp/corefcn/toplev.cc, libinterp/corefcn/toplev.h,
libinterp/corefcn/tril.cc, libinterp/corefcn/txt-eng-ft.cc,
libinterp/corefcn/txt-eng-ft.h, libinterp/corefcn/txt-eng.h,
libinterp/corefcn/typecast.cc, libinterp/corefcn/urlwrite.cc,
libinterp/corefcn/utils.cc, libinterp/corefcn/variables.cc,
libinterp/corefcn/variables.h, libinterp/corefcn/xdiv.cc,
libinterp/corefcn/xdiv.h, libinterp/corefcn/xnorm.h, libinterp/corefcn/xpow.cc,
libinterp/corefcn/xpow.h, libinterp/corefcn/zfstream.cc,
libinterp/corefcn/zfstream.h, libinterp/dldfcn/__delaunayn__.cc,
libinterp/dldfcn/__dsearchn__.cc, libinterp/dldfcn/__eigs__.cc,
libinterp/dldfcn/__fltk_uigetfile__.cc, libinterp/dldfcn/__glpk__.cc,
libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/__init_gnuplot__.cc,
libinterp/dldfcn/__magick_read__.cc, libinterp/dldfcn/__voronoi__.cc,
libinterp/dldfcn/amd.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/chol.cc,
libinterp/dldfcn/colamd.cc, libinterp/dldfcn/convhulln.cc,
libinterp/dldfcn/dmperm.cc, libinterp/dldfcn/fftw.cc, libinterp/dldfcn/qr.cc,
libinterp/dldfcn/symbfact.cc, libinterp/dldfcn/symrcm.cc,
libinterp/dldfcn/tsearch.cc, libinterp/octave-value/ov-base-diag.cc,
libinterp/octave-value/ov-base-diag.h, libinterp/octave-value/ov-base-int.cc,
libinterp/octave-value/ov-base-int.h, libinterp/octave-value/ov-base-mat.h,
libinterp/octave-value/ov-base-scalar.cc,
libinterp/octave-value/ov-base-scalar.h,
libinterp/octave-value/ov-base-sparse.cc,
libinterp/octave-value/ov-base-sparse.h, libinterp/octave-value/ov-base.cc,
libinterp/octave-value/ov-base.h, libinterp/octave-value/ov-bool-mat.cc,
libinterp/octave-value/ov-bool-mat.h, libinterp/octave-value/ov-bool-sparse.cc,
libinterp/octave-value/ov-bool-sparse.h, libinterp/octave-value/ov-bool.cc,
libinterp/octave-value/ov-bool.h, libinterp/octave-value/ov-builtin.cc,
libinterp/octave-value/ov-builtin.h, libinterp/octave-value/ov-cell.cc,
libinterp/octave-value/ov-cell.h, libinterp/octave-value/ov-ch-mat.cc,
libinterp/octave-value/ov-ch-mat.h, libinterp/octave-value/ov-class.cc,
libinterp/octave-value/ov-class.h, libinterp/octave-value/ov-colon.h,
libinterp/octave-value/ov-complex.cc, libinterp/octave-value/ov-complex.h,
libinterp/octave-value/ov-cx-diag.cc, libinterp/octave-value/ov-cx-diag.h,
libinterp/octave-value/ov-cx-mat.cc, libinterp/octave-value/ov-cx-mat.h,
libinterp/octave-value/ov-cx-sparse.cc, libinterp/octave-value/ov-cx-sparse.h,
libinterp/octave-value/ov-dld-fcn.h, libinterp/octave-value/ov-fcn-handle.cc,
libinterp/octave-value/ov-fcn-handle.h,
libinterp/octave-value/ov-fcn-inline.cc,
libinterp/octave-value/ov-fcn-inline.h, libinterp/octave-value/ov-fcn.h,
libinterp/octave-value/ov-float.cc, libinterp/octave-value/ov-float.h,
libinterp/octave-value/ov-flt-complex.cc,
libinterp/octave-value/ov-flt-complex.h,
libinterp/octave-value/ov-flt-cx-diag.cc,
libinterp/octave-value/ov-flt-cx-diag.h,
libinterp/octave-value/ov-flt-cx-mat.cc,
libinterp/octave-value/ov-flt-cx-mat.h,
libinterp/octave-value/ov-flt-re-diag.cc,
libinterp/octave-value/ov-flt-re-diag.h,
libinterp/octave-value/ov-flt-re-mat.cc,
libinterp/octave-value/ov-flt-re-mat.h, libinterp/octave-value/ov-int16.cc,
libinterp/octave-value/ov-int32.cc, libinterp/octave-value/ov-int64.cc,
libinterp/octave-value/ov-int8.cc, libinterp/octave-value/ov-intx.h,
libinterp/octave-value/ov-java.cc, libinterp/octave-value/ov-lazy-idx.h,
libinterp/octave-value/ov-mex-fcn.cc, libinterp/octave-value/ov-mex-fcn.h,
libinterp/octave-value/ov-null-mat.cc, libinterp/octave-value/ov-null-mat.h,
libinterp/octave-value/ov-oncleanup.cc, libinterp/octave-value/ov-perm.cc,
libinterp/octave-value/ov-perm.h, libinterp/octave-value/ov-range.cc,
libinterp/octave-value/ov-range.h, libinterp/octave-value/ov-re-diag.cc,
libinterp/octave-value/ov-re-diag.h, libinterp/octave-value/ov-re-mat.cc,
libinterp/octave-value/ov-re-mat.h, libinterp/octave-value/ov-re-sparse.cc,
libinterp/octave-value/ov-re-sparse.h, libinterp/octave-value/ov-scalar.cc,
libinterp/octave-value/ov-scalar.h, libinterp/octave-value/ov-str-mat.cc,
libinterp/octave-value/ov-str-mat.h, libinterp/octave-value/ov-struct.cc,
libinterp/octave-value/ov-struct.h, libinterp/octave-value/ov-type-conv.h,
libinterp/octave-value/ov-typeinfo.cc, libinterp/octave-value/ov-typeinfo.h,
libinterp/octave-value/ov-uint16.cc, libinterp/octave-value/ov-uint32.cc,
libinterp/octave-value/ov-uint64.cc, libinterp/octave-value/ov-uint8.cc,
libinterp/octave-value/ov-usr-fcn.cc, libinterp/octave-value/ov-usr-fcn.h,
libinterp/octave-value/ov.cc, libinterp/octave-value/ov.h, libinterp/octave.cc,
libinterp/operators/op-b-bm.cc, libinterp/operators/op-b-sbm.cc,
libinterp/operators/op-bm-b.cc, libinterp/operators/op-bm-bm.cc,
libinterp/operators/op-cdm-cdm.cc, libinterp/operators/op-chm.cc,
libinterp/operators/op-class.cc, libinterp/operators/op-cm-cm.cc,
libinterp/operators/op-cm-cs.cc, libinterp/operators/op-cm-s.cc,
libinterp/operators/op-cm-scm.cc, libinterp/operators/op-cm-sm.cc,
libinterp/operators/op-cs-cm.cc, libinterp/operators/op-cs-cs.cc,
libinterp/operators/op-cs-scm.cc, libinterp/operators/op-cs-sm.cc,
libinterp/operators/op-dm-dm.cc, libinterp/operators/op-dm-scm.cc,
libinterp/operators/op-double-conv.cc, libinterp/operators/op-fcdm-fcdm.cc,
libinterp/operators/op-fcm-fcm.cc, libinterp/operators/op-fcm-fcs.cc,
libinterp/operators/op-fcm-fm.cc, libinterp/operators/op-fcm-fs.cc,
libinterp/operators/op-fcs-fcm.cc, libinterp/operators/op-fcs-fcs.cc,
libinterp/operators/op-fcs-fm.cc, libinterp/operators/op-fcs-fs.cc,
libinterp/operators/op-fdm-fdm.cc, libinterp/operators/op-float-conv.cc,
libinterp/operators/op-fm-fcm.cc, libinterp/operators/op-fm-fcs.cc,
libinterp/operators/op-fm-fm.cc, libinterp/operators/op-fm-fs.cc,
libinterp/operators/op-fs-fcm.cc, libinterp/operators/op-fs-fcs.cc,
libinterp/operators/op-fs-fm.cc, libinterp/operators/op-fs-fs.cc,
libinterp/operators/op-m-cm.cc, libinterp/operators/op-m-cs.cc,
libinterp/operators/op-m-m.cc, libinterp/operators/op-m-s.cc,
libinterp/operators/op-m-scm.cc, libinterp/operators/op-m-sm.cc,
libinterp/operators/op-pm-scm.cc, libinterp/operators/op-range.cc,
libinterp/operators/op-s-cm.cc, libinterp/operators/op-s-cs.cc,
libinterp/operators/op-s-scm.cc, libinterp/operators/op-sbm-b.cc,
libinterp/operators/op-sbm-bm.cc, libinterp/operators/op-sbm-sbm.cc,
libinterp/operators/op-scm-cm.cc, libinterp/operators/op-scm-cs.cc,
libinterp/operators/op-scm-m.cc, libinterp/operators/op-scm-s.cc,
libinterp/operators/op-scm-scm.cc, libinterp/operators/op-scm-sm.cc,
libinterp/operators/op-sm-cm.cc, libinterp/operators/op-sm-m.cc,
libinterp/operators/op-sm-s.cc, libinterp/operators/op-sm-scm.cc,
libinterp/operators/op-sm-sm.cc, libinterp/operators/op-str-m.cc,
libinterp/operators/op-str-s.cc, libinterp/operators/op-str-str.cc,
libinterp/operators/ops.h, libinterp/parse-tree/lex.h,
libinterp/parse-tree/parse.h, libinterp/parse-tree/pt-arg-list.cc,
libinterp/parse-tree/pt-arg-list.h, libinterp/parse-tree/pt-assign.cc,
libinterp/parse-tree/pt-assign.h, libinterp/parse-tree/pt-binop.cc,
libinterp/parse-tree/pt-binop.h, libinterp/parse-tree/pt-bp.h,
libinterp/parse-tree/pt-cbinop.cc, libinterp/parse-tree/pt-check.cc,
libinterp/parse-tree/pt-colon.cc, libinterp/parse-tree/pt-colon.h,
libinterp/parse-tree/pt-const.cc, libinterp/parse-tree/pt-decl.cc,
libinterp/parse-tree/pt-decl.h, libinterp/parse-tree/pt-eval.cc,
libinterp/parse-tree/pt-except.h, libinterp/parse-tree/pt-exp.h,
libinterp/parse-tree/pt-fcn-handle.cc, libinterp/parse-tree/pt-id.cc,
libinterp/parse-tree/pt-id.h, libinterp/parse-tree/pt-idx.cc,
libinterp/parse-tree/pt-idx.h, libinterp/parse-tree/pt-loop.h,
libinterp/parse-tree/pt-mat.cc, libinterp/parse-tree/pt-misc.cc,
libinterp/parse-tree/pt-misc.h, libinterp/parse-tree/pt-pr-code.cc,
libinterp/parse-tree/pt-select.h, libinterp/parse-tree/pt-stmt.h,
libinterp/parse-tree/token.h, libinterp/version.cc:
Use GNU style coding conventions for code in libinterp/
author | Rik <rik@octave.org> |
---|---|
date | Mon, 28 Oct 2013 19:51:46 -0700 |
parents | d63878346099 |
children | b155fad47055 |
line wrap: on
line source
/* Copyright (C) 1996-2013 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 <string> #include "CmplxSCHUR.h" #include "dbleSCHUR.h" #include "fCmplxSCHUR.h" #include "floatSCHUR.h" #include "defun.h" #include "error.h" #include "gripes.h" #include "oct-obj.h" #include "utils.h" template <class Matrix> static octave_value mark_upper_triangular (const Matrix& a) { octave_value retval = a; octave_idx_type n = a.rows (); assert (a.columns () == n); const typename Matrix::element_type zero = typename Matrix::element_type (); for (octave_idx_type i = 0; i < n; i++) if (a(i,i) == zero) return retval; retval.matrix_type (MatrixType::Upper); return retval; } DEFUN (schur, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Built-in Function} {@var{S} =} schur (@var{A})\n\ @deftypefnx {Built-in Function} {@var{S} =} schur (@var{A}, \"real\")\n\ @deftypefnx {Built-in Function} {@var{S} =} schur (@var{A}, \"complex\")\n\ @deftypefnx {Built-in Function} {@var{S} =} schur (@var{A}, @var{opt})\n\ @deftypefnx {Built-in Function} {[@var{U}, @var{S}] =} schur (@var{A}, @dots{})\n\ @cindex Schur decomposition\n\ Compute the Schur@tie{}decomposition of @var{A}\n\ @tex\n\ $$\n\ S = U^T A U\n\ $$\n\ @end tex\n\ @ifnottex\n\ \n\ @example\n\ @code{@var{S} = @var{U}' * @var{A} * @var{U}}\n\ @end example\n\ \n\ @end ifnottex\n\ where @var{U} is a unitary matrix\n\ @tex\n\ ($U^T U$ is identity)\n\ @end tex\n\ @ifnottex\n\ (@code{@var{U}'* @var{U}} is identity)\n\ @end ifnottex\n\ and @var{S} is upper triangular. The eigenvalues of @var{A} (and @var{S})\n\ are the diagonal elements of @var{S}. If the matrix @var{A}\n\ is real, then the real Schur@tie{}decomposition is computed, in which the\n\ matrix @var{U} is orthogonal and @var{S} is block upper triangular\n\ with blocks of size at most\n\ @tex\n\ $2 \\times 2$\n\ @end tex\n\ @ifnottex\n\ @code{2 x 2}\n\ @end ifnottex\n\ along the diagonal. The diagonal elements of @var{S}\n\ (or the eigenvalues of the\n\ @tex\n\ $2 \\times 2$\n\ @end tex\n\ @ifnottex\n\ @code{2 x 2}\n\ @end ifnottex\n\ blocks, when appropriate) are the eigenvalues of @var{A} and @var{S}.\n\ \n\ The default for real matrices is a real Schur@tie{}decomposition.\n\ A complex decomposition may be forced by passing the flag\n\ @qcode{\"complex\"}.\n\ \n\ The eigenvalues are optionally ordered along the diagonal according to\n\ the value of @var{opt}. @code{@var{opt} = \"a\"} indicates that all\n\ eigenvalues with negative real parts should be moved to the leading\n\ block of @var{S}\n\ (used in @code{are}), @code{@var{opt} = \"d\"} indicates that all eigenvalues\n\ with magnitude less than one should be moved to the leading block of @var{S}\n\ (used in @code{dare}), and @code{@var{opt} = \"u\"}, the default, indicates\n\ that no ordering of eigenvalues should occur. The leading @var{k}\n\ columns of @var{U} always span the @var{A}-invariant\n\ subspace corresponding to the @var{k} leading eigenvalues of @var{S}.\n\ \n\ The Schur@tie{}decomposition is used to compute eigenvalues of a\n\ square matrix, and has applications in the solution of algebraic\n\ Riccati equations in control (see @code{are} and @code{dare}).\n\ @seealso{rsf2csf, lu, chol, hess, qr, qz, svd}\n\ @end deftypefn") { octave_value_list retval; int nargin = args.length (); if (nargin < 1 || nargin > 2 || nargout > 2) { print_usage (); return retval; } octave_value arg = args(0); std::string ord; if (nargin == 2) { ord = args(1).string_value (); if (error_state) { error ("schur: second argument must be a string"); return retval; } } bool force_complex = false; if (ord == "real") { ord = std::string (); } else if (ord == "complex") { force_complex = true; ord = std::string (); } else { char ord_char = ord.empty () ? 'U' : ord[0]; if (ord_char != 'U' && ord_char != 'A' && ord_char != 'D' && ord_char != 'u' && ord_char != 'a' && ord_char != 'd') { warning ("schur: incorrect ordered schur argument '%c'", ord.c_str ()); return retval; } } octave_idx_type nr = arg.rows (); octave_idx_type nc = arg.columns (); if (nr != nc) { gripe_square_matrix_required ("schur"); return retval; } if (! arg.is_numeric_type ()) gripe_wrong_type_arg ("schur", arg); else if (arg.is_single_type ()) { if (! force_complex && arg.is_real_type ()) { FloatMatrix tmp = arg.float_matrix_value (); if (! error_state) { if (nargout == 0 || nargout == 1) { FloatSCHUR result (tmp, ord, false); retval(0) = result.schur_matrix (); } else { FloatSCHUR result (tmp, ord, true); retval(1) = result.schur_matrix (); retval(0) = result.unitary_matrix (); } } } else { FloatComplexMatrix ctmp = arg.float_complex_matrix_value (); if (! error_state) { if (nargout == 0 || nargout == 1) { FloatComplexSCHUR result (ctmp, ord, false); retval(0) = mark_upper_triangular (result.schur_matrix ()); } else { FloatComplexSCHUR result (ctmp, ord, true); retval(1) = mark_upper_triangular (result.schur_matrix ()); retval(0) = result.unitary_matrix (); } } } } else { if (! force_complex && arg.is_real_type ()) { Matrix tmp = arg.matrix_value (); if (! error_state) { if (nargout == 0 || nargout == 1) { SCHUR result (tmp, ord, false); retval(0) = result.schur_matrix (); } else { SCHUR result (tmp, ord, true); retval(1) = result.schur_matrix (); retval(0) = result.unitary_matrix (); } } } else { ComplexMatrix ctmp = arg.complex_matrix_value (); if (! error_state) { if (nargout == 0 || nargout == 1) { ComplexSCHUR result (ctmp, ord, false); retval(0) = mark_upper_triangular (result.schur_matrix ()); } else { ComplexSCHUR result (ctmp, ord, true); retval(1) = mark_upper_triangular (result.schur_matrix ()); retval(0) = result.unitary_matrix (); } } } } return retval; } /* %!test %! a = [1, 2, 3; 4, 5, 9; 7, 8, 6]; %! [u, s] = schur (a); %! assert (u' * a * u, s, sqrt (eps)); %!test %! a = single ([1, 2, 3; 4, 5, 9; 7, 8, 6]); %! [u, s] = schur (a); %! assert (u' * a * u, s, sqrt (eps ("single"))); %!test %! fail ("schur ([1, 2; 3, 4], 2)", "warning"); %!error schur () %!error <argument must be a square matrix> schur ([1, 2, 3; 4, 5, 6]) */ DEFUN (rsf2csf, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Function File} {[@var{U}, @var{T}] =} rsf2csf (@var{UR}, @var{TR})\n\ Convert a real, upper quasi-triangular Schur@tie{}form @var{TR} to a complex,\n\ upper triangular Schur@tie{}form @var{T}.\n\ \n\ Note that the following relations hold:\n\ \n\ @tex\n\ $UR \\cdot TR \\cdot {UR}^T = U T U^{\\dagger}$ and\n\ $U^{\\dagger} U$ is the identity matrix I.\n\ @end tex\n\ @ifnottex\n\ @tcode{@var{UR} * @var{TR} * @var{UR}' = @var{U} * @var{T} * @var{U}'} and\n\ @code{@var{U}' * @var{U}} is the identity matrix I.\n\ @end ifnottex\n\ \n\ Note also that @var{U} and @var{T} are not unique.\n\ @seealso{schur}\n\ @end deftypefn") { octave_value_list retval; if (args.length () == 2 && nargout <= 2) { if (! args(0).is_numeric_type ()) gripe_wrong_type_arg ("rsf2csf", args(0)); else if (! args(1).is_numeric_type ()) gripe_wrong_type_arg ("rsf2csf", args(1)); else if (args(0).is_complex_type () || args(1).is_complex_type ()) error ("rsf2csf: UR and TR must be real matrices"); else { if (args(0).is_single_type () || args(1).is_single_type ()) { FloatMatrix u = args(0).float_matrix_value (); FloatMatrix t = args(1).float_matrix_value (); if (! error_state) { FloatComplexSCHUR cs (FloatSCHUR (t, u)); retval(1) = cs.schur_matrix (); retval(0) = cs.unitary_matrix (); } } else { Matrix u = args(0).matrix_value (); Matrix t = args(1).matrix_value (); if (! error_state) { ComplexSCHUR cs (SCHUR (t, u)); retval(1) = cs.schur_matrix (); retval(0) = cs.unitary_matrix (); } } } } else print_usage (); return retval; } /* %!test %! A = [1, 1, 1, 2; 1, 2, 1, 1; 1, 1, 3, 1; -2, 1, 1, 1]; %! [u, t] = schur (A); %! [U, T] = rsf2csf (u, t); %! assert (norm (u * t * u' - U * T * U'), 0, 1e-12); %! assert (norm (A - U * T * U'), 0, 1e-12); %!test %! A = rand (10); %! [u, t] = schur (A); %! [U, T] = rsf2csf (u, t); %! assert (norm (tril (T, -1)), 0); %! assert (norm (U * U'), 1, 1e-14); %!test %! A = [0, 1;-1, 0]; %! [u, t] = schur (A); %! [U, T] = rsf2csf (u,t); %! assert (U * T * U', A, 1e-14); */