Mercurial > octave-nkf
view scripts/statistics/distributions/poisson_cdf.m @ 3426:f8dde1807dee
[project @ 2000-01-13 08:40:00 by jwe]
author | jwe |
---|---|
date | Thu, 13 Jan 2000 08:40:53 +0000 |
parents | 42cb61dd0248 |
children | 434790acb067 |
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## 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: poisson_cdf (x, lambda) ## ## For each element of x, compute the cumulative distribution function ## (CDF) at x of the Poisson distribution with parameter lambda. ## Author: KH <Kurt.Hornik@ci.tuwien.ac.at> ## Description: CDF of the Poisson distribution function cdf = poisson_cdf (x, l) if (nargin != 2) usage ("poisson_cdf (x, lambda)"); endif [retval, x, l] = common_size (x, l); if (retval > 0) error ("poisson_cdf: x and lambda must be of common size or scalar"); endif [r, c] = size (x); s = r * c; x = reshape (x, 1, s); l = reshape (l, 1, s); cdf = zeros (1, s); k = find (isnan (x) | !(l > 0)); if any (k) cdf(k) = NaN * ones (1, length (k)); endif k = find ((x == Inf) & (l > 0)); if any (k) cdf(k) = ones (1, length (k)); endif k = find ((x >= 0) & (x < Inf) & (l > 0)); if any (k) cdf(k) = 1 - gammai (floor (x(k)) + 1, l(k)); endif cdf = reshape (cdf, r, c); endfunction