Mercurial > hg > octave-lyh
view scripts/specfun/factorial.m @ 6451:fdcb715e381c
[project @ 2007-03-24 17:54:23 by jwe]
author | jwe |
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date | Sat, 24 Mar 2007 17:54:23 +0000 |
parents | 3f3e86e9fb57 |
children | 25cad08843a0 |
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## Copyright (C) 2000 Paul Kienzle ## ## 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 2, 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, write to the Free ## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA ## 02110-1301, USA. ## -*- texinfo -*- ## @deftypefn {Function File} {} factorial (@var{n}) ## Return the factorial of @var{n}. If @var{n} is scalar, this is ## equivalent to @code{prod (1:@var{n})}. If @var{n} is an array, ## the factorial of the elements of the array are returned. ## @end deftypefn function x = factorial (n) if (nargin != 1) print_usage (); elseif (any (n(:) < 0)) error ("factorial: n be be a scalar or array of positive integers"); endif if (isscalar (n)) x = prod (2:n); else n (n < 1) = 1; m = max (n(:)); c = cumprod (1:m); x = c(floor (n)); endif endfunction