1 ## Copyright (C) 2004-2012 David Bateman and Andy Adler
3 ## This file is part of Octave.
5 ## Octave is free software; you can redistribute it and/or modify it
6 ## under the terms of the GNU General Public License as published by
7 ## the Free Software Foundation; either version 3 of the License, or (at
8 ## your option) any later version.
10 ## Octave is distributed in the hope that it will be useful, but
11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 ## General Public License for more details.
15 ## You should have received a copy of the GNU General Public License
16 ## along with Octave; see the file COPYING. If not, see
17 ## <http://www.gnu.org/licenses/>.
20 ## @deftypefn {Function File} {@var{x} =} spconvert (@var{m})
21 ## This function converts for a simple sparse matrix format easily
22 ## produced by other programs into Octave's internal sparse format. The
23 ## input @var{x} is either a 3 or 4 column real matrix, containing
24 ## the row, column, real and imaginary parts of the elements of the
25 ## sparse matrix. An element with a zero real and imaginary part can
26 ## be used to force a particular matrix size.
29 function s = spconvert (m)
35 if (nargin != 1 || ! ismatrix (m) || ! isreal (m)
36 || length (sz) != 2 || (sz(2) != 3 && sz(2) != 4))
37 error ("spconvert: argument must be sparse or real matrix with 3 or 4 columns");
39 s = sparse (m(:,1), m(:,2), m(:,3));
41 s = sparse (m(:,1), m(:,2), m(:,3) + 1i*m(:,4));
52 %! s = spconvert ([i, j, v]);
53 %! assert (issparse (s));
54 %! [fi, fj, fv] = find (s);
55 %! assert (isequal (i, fi) && isequal (j, fj) && isequal (v, fv));
56 %! s = spconvert ([i, j, v, j]);
57 %! [fi, fj, fv] = find (s);
58 %! assert (isequal (i, fi) && isequal (j, fj) && isequal (complex (v, j), fv));
59 %! assert (size (spconvert ([1, 1, 3; 5, 15, 0])), [5, 15]);
61 %% Test input validation
63 %!error spconvert (1, 2)
64 %!error spconvert ({[1 2 3]})
65 %!error spconvert ([1 2])
66 %!error spconvert ([1 2 3i])
67 %!error spconvert ([1 2 3 4 5])