Mercurial > octave-nkf
view scripts/specfun/factorial.m @ 20266:83792dd9bcc1
Use in-place operators in m-files where possible.
* scripts/audio/@audioplayer/set.m, scripts/audio/@audiorecorder/set.m,
scripts/audio/mu2lin.m, scripts/elfun/cosd.m, scripts/general/del2.m,
scripts/general/profexplore.m, scripts/general/quadl.m, scripts/general/rat.m,
scripts/general/rotdim.m, scripts/help/get_first_help_sentence.m,
scripts/help/private/__strip_html_tags__.m, scripts/image/cubehelix.m,
scripts/io/textread.m, scripts/linear-algebra/duplication_matrix.m,
scripts/linear-algebra/housh.m, scripts/linear-algebra/krylov.m,
scripts/linear-algebra/logm.m, scripts/linear-algebra/normest.m,
scripts/linear-algebra/onenormest.m, scripts/optimization/fminsearch.m,
scripts/optimization/lsqnonneg.m, scripts/optimization/qp.m,
scripts/plot/appearance/annotation.m, scripts/plot/appearance/axis.m,
scripts/plot/appearance/legend.m, scripts/plot/appearance/specular.m,
scripts/plot/draw/colorbar.m, scripts/plot/draw/hist.m,
scripts/plot/draw/plotmatrix.m, scripts/plot/draw/private/__stem__.m,
scripts/plot/util/__actual_axis_position__.m,
scripts/plot/util/__gnuplot_drawnow__.m, scripts/plot/util/findobj.m,
scripts/plot/util/print.m, scripts/plot/util/private/__go_draw_axes__.m,
scripts/plot/util/private/__print_parse_opts__.m, scripts/plot/util/rotate.m,
scripts/polynomial/pchip.m, scripts/polynomial/polyaffine.m,
scripts/polynomial/polyder.m, scripts/polynomial/private/__splinefit__.m,
scripts/polynomial/residue.m, scripts/signal/arch_fit.m,
scripts/signal/arch_rnd.m, scripts/signal/bartlett.m,
scripts/signal/blackman.m, scripts/signal/freqz.m, scripts/signal/hamming.m,
scripts/signal/hanning.m, scripts/signal/spectral_adf.m,
scripts/signal/spectral_xdf.m, scripts/signal/stft.m,
scripts/sparse/bicgstab.m, scripts/sparse/cgs.m,
scripts/sparse/private/__sprand_impl__.m, scripts/sparse/qmr.m,
scripts/sparse/sprandsym.m, scripts/sparse/svds.m, scripts/specfun/legendre.m,
scripts/special-matrix/gallery.m, scripts/statistics/base/gls.m,
scripts/statistics/models/logistic_regression.m,
scripts/statistics/tests/kruskal_wallis_test.m,
scripts/statistics/tests/manova.m, scripts/statistics/tests/wilcoxon_test.m,
scripts/time/datevec.m:
Use in-place operators in m-files where possible.
author | Rik <rik@octave.org> |
---|---|
date | Tue, 26 May 2015 21:07:42 -0700 |
parents | 4197fc428c7d |
children |
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## Copyright (C) 2000-2015 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 3 of the License, 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, see ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} factorial (@var{n}) ## Return the factorial of @var{n} where @var{n} is a real non-negative integer. ## ## If @var{n} is a scalar, this is equivalent to @code{prod (1:@var{n})}. For ## vector or matrix arguments, return the factorial of each element in the ## array. ## ## For non-integers see the generalized factorial function @code{gamma}. ## Note that the factorial function grows large quite quickly, and even ## with double precision values overflow will occur if @var{n} > 171. For ## such cases consider @code{gammaln}. ## @seealso{prod, gamma, gammaln} ## @end deftypefn function x = factorial (n) if (nargin != 1) print_usage (); elseif (! isreal (n) || any (n(:) < 0 | n(:) != fix (n(:)))) error ("factorial: all N must be real non-negative integers"); endif x = round (gamma (n+1)); ## FIXME: Matlab returns an output of the same type as the input. ## This doesn't seem particularly worth copying--for example uint8 would ## saturate for n > 5. If desired, however, the following code could be ## uncommented. # if (! isfloat (x)) # x = cast (x, class (n)); # endif endfunction %!assert (factorial (5), prod (1:5)) %!assert (factorial ([1,2;3,4]), [1,2;6,24]) %!assert (factorial (70), exp (sum (log (1:70))), -128*eps) %!assert (factorial (0), 1) %!error factorial () %!error factorial (1,2) %!error <must be real non-negative integers> factorial (2i) %!error <must be real non-negative integers> factorial (-3) %!error <must be real non-negative integers> factorial (5.5)