## Copyright (C) 1995, 1996, 1997 Kurt Hornik ## ## This program 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. ## ## This program 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 this file. If not, write to the Free Software Foundation, ## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ## usage: gamma_cdf (x, a, b) ## ## For each element of x, compute the cumulative distribution function ## (CDF) at x of the Gamma distribution with parameters a and b. ## Author: TT <Teresa.Twaroch@ci.tuwien.ac.at> ## Description: CDF of the Gamma distribution function cdf = gamma_cdf (x, a, b) if (nargin != 3) usage ("gamma_cdf (x, a, b)"); endif [retval, x, a, b] = common_size (x, a, b); if (retval > 0) error ("gamma_cdf: x, a and b must be of common size or scalars"); endif [r, c] = size (x); s = r * c; x = reshape (x, s, 1); a = reshape (a, s, 1); b = reshape (b, s, 1); cdf = zeros (s, 1); k = find (!(a > 0) | !(b > 0) | isnan (x)); if any (k) cdf (k) = NaN * ones (length (k), 1); endif k = find ((x > 0) & (a > 0) & (b > 0)); if any (k) cdf (k) = gammai (a(k), b(k) .* x(k)); endif cdf = reshape (cdf, r, c); endfunction

Generated by Doxygen 1.6.0 Back to index