Mercurial > octave-nkf
view scripts/statistics/distributions/gamcdf.m @ 7016:93c65f2a5668
[project @ 2007-10-12 06:40:56 by jwe]
author | jwe |
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date | Fri, 12 Oct 2007 06:41:26 +0000 |
parents | 4775fc1aa728 |
children | a1dbe9d80eee |
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## Copyright (C) 1995, 1996, 1997 Kurt Hornik ## ## 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} {} gamcdf (@var{x}, @var{a}, @var{b}) ## For each element of @var{x}, compute the cumulative distribution ## function (CDF) at @var{x} of the Gamma distribution with parameters ## @var{a} and @var{b}. ## @seealso{gamma, gammaln, gammainc, gampdf, gaminv, gamrnd} ## @end deftypefn ## Author: TT <Teresa.Twaroch@ci.tuwien.ac.at> ## Description: CDF of the Gamma distribution function cdf = gamcdf (x, a, b) if (nargin != 3) print_usage (); endif if (!isscalar (a) || !isscalar(b)) [retval, x, a, b] = common_size (x, a, b); if (retval > 0) error ("gamcdf: x, a and b must be of common size or scalars"); endif endif sz = size (x); cdf = zeros (sz); k = find (!(a > 0) | !(b > 0) | isnan (x)); if (any (k)) cdf (k) = NaN; endif k = find ((x > 0) & (a > 0) & (b > 0)); if (any (k)) if (isscalar (a) && isscalar(b)) cdf (k) = gammainc (x(k) ./ b, a); else cdf (k) = gammainc (x(k) ./ b(k), a(k)); endif endif endfunction