Mercurial > octave-antonio
view scripts/sparse/colperm.m @ 20170:af2b7695f1c4 draft default tip @
gallery.m: clean and vectorize part of qmult.
* scripts/special-matrix/gallery.m: make qmult() follow Octave guidelines, vectorize last for loop in qmult().
author | Antonio Pino Robles <data.script93@gmail.com> |
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date | Thu, 28 May 2015 18:32:47 +0200 |
parents | 4197fc428c7d |
children | df437a52bcaf |
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## Copyright (C) 2004-2015 David Bateman and Andy Adler ## ## 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/>. ## -*- texinfo -*- ## @deftypefn {Function File} {@var{p} =} colperm (@var{s}) ## Return the column permutations such that the columns of ## @code{@var{s} (:, @var{p})} are ordered in terms of increase number ## of nonzero elements. If @var{s} is symmetric, then @var{p} is chosen ## such that @code{@var{s} (@var{p}, @var{p})} orders the rows and ## columns with increasing number of nonzeros elements. ## @end deftypefn function p = colperm (s) if (nargin != 1) print_usage (); endif [i, j] = find (s); idx = find (diff ([j; Inf]) != 0); [dummy, p] = sort (idx - [0; idx(1:(end-1))]); endfunction