Mercurial > octave-nkf
view scripts/sparse/speye.m @ 20651:e54ecb33727e
lo-array-gripes.cc: Remove FIXME's related to buffer size.
* lo-array-gripes.cc: Remove FIXME's related to buffer size. Shorten sprintf
buffers from 100 to 64 characters (still well more than 19 required).
Use 'const' decorator on constant value for clarity. Remove extra space
between variable and array bracket.
author | Rik <rik@octave.org> |
---|---|
date | Mon, 12 Oct 2015 21:13:47 -0700 |
parents | 4197fc428c7d |
children |
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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{s} =} speye (@var{m}, @var{n}) ## @deftypefnx {Function File} {@var{s} =} speye (@var{m}) ## @deftypefnx {Function File} {@var{s} =} speye (@var{sz}) ## Return a sparse identity matrix of size @var{m}x@var{n}. ## ## The implementation is significantly more efficient than ## @code{sparse (eye (@var{m}))} as the full matrix is not constructed. ## ## Called with a single argument a square matrix of size ## @var{m}-by-@var{m} is created. If called with a single vector argument ## @var{sz}, this argument is taken to be the size of the matrix to create. ## @seealso{sparse, spdiags, eye} ## @end deftypefn function s = speye (m, n) if (nargin == 1) if (isvector (m) && length (m) == 2) n = m(2); m = m(1); elseif (isscalar (m)) n = m; else error ("speye: invalid matrix dimension"); endif else if (! isscalar (m) || ! isscalar (n)) error ("speye: invalid matrix dimension"); endif endif lo = min ([m, n]); s = sparse (1:lo, 1:lo, 1, m, n); endfunction %!assert (issparse (speye (4))) %!assert (speye (4), sparse (1:4,1:4,1)) %!assert (speye (2,4), sparse (1:2,1:2,1,2,4)) %!assert (speye (4,2), sparse (1:2,1:2,1,4,2)) %!assert (speye ([4,2]), sparse (1:2,1:2,1,4,2))