1 ## Copyright (C) 2010 Soren Hauberg
3 ## This program is free software; you can redistribute it and/or modify
4 ## it under the terms of the GNU General Public License as published by
5 ## the Free Software Foundation; either version 3, or (at your option)
8 ## This program is distributed in the hope that it will be useful, but
9 ## WITHOUT ANY WARRANTY; without even the implied warranty of
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 ## General Public License for more details.
13 ## You should have received a copy of the GNU General Public License
14 ## along with this file. If not, see <http://www.gnu.org/licenses/>.
17 ## @deftypefn {Function File} minus (@var{a}, @var{a})
18 ## Return the difference between a Kronecker product and another matrix. This is performed
19 ## by forming the full matrix of both inputs and is as such a potential expensive
21 ## @seealso{minus, @@kronprod/plus}
24 function retval = minus (M1, M2)
29 if (!ismatrix (M1) || !ismatrix (M2))
30 error ("minus: both input arguments must be matrices");
33 if (!size_equal (M1, M2))
34 error ("minus: nonconformant arguments (op1 is %dx%d, op2 is %dx%d)",
35 rows (M1), columns (M1), rows (M2), columns (M2));
38 ## XXX: Can we do something smarter here?