1 ## Copyright (C) 2008 VZLU Prague, a.s., Czech Republic
3 ## This program is free software; you can redistribute it and/or modify it under
4 ## the terms of the GNU General Public License as published by the Free Software
5 ## Foundation; either version 3 of the License, or (at your option) any later
8 ## This program is distributed in the hope that it will be useful, but WITHOUT
9 ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
13 ## You should have received a copy of the GNU General Public License along with
14 ## this program; if not, see <http://www.gnu.org/licenses/>.
17 ## @deftypefn{Function File} {@var{p} =} safeprod (@var{x}, @var{dim})
18 ## @deftypefnx{Function File} {[@var{p}, @var{e}] =} safeprod (@var{x}, @var{dim})
19 ## This function forms product(s) of elements of the array @var{x} along the dimension
20 ## specified by @var{dim}, analogically to @code{prod}, but avoids overflows and underflows
21 ## if possible. If called with 2 output arguments, @var{p} and @var{e} are computed
22 ## so that the product is @code{@var{p} * 2^@var{e}}.
23 ## @seealso{prod,log2}
26 ## Author: Jaroslav Hajek <highegg@gmail.com>
28 function [p, e] = safeprod (x, dim)
29 if (nargin < 1 || nargin > 2)
41 % try the normal algorithm first
48 % 0, Inf and NaN are possibly problematic results. If detected, use the safe
51 flag = (p == 0 | ! isfinite (p));