1% Create a sparse matrix which packs an array under the control of a mask.
2%
3% H = sparse_pack(mask)
4%
5% Create a sparse matrix H which packs an array. It selects the elements where
6% mask is true.
7
8function H = sparse_pack(mask)
9
10
11j = find(mask)';
12m = length(j);
13i = 1:m;
14s = ones(1,m);
15
16n = numel(mask);
17
18%whos i j s
19H = sparse(i,j,s,m,n);
20
21% Copyright (C) 2009 Alexander Barth <a.barth@ulg.ac.be>
22%
23% This program is free software; you can redistribute it and/or modify
24% it under the terms of the GNU General Public License as published by
25% the Free Software Foundation; either version 2 of the License, or
26% (at your option) any later version.
27%
28% This program is distributed in the hope that it will be useful,
29% but WITHOUT ANY WARRANTY; without even the implied warranty of
30% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
31% GNU General Public License for more details.
32%
33% You should have received a copy of the GNU General Public License
34% along with this program; If not, see <http://www.gnu.org/licenses/>.
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