Mercurial > octave
view scripts/statistics/distributions/binomial_rnd.m @ 3426:f8dde1807dee
[project @ 2000-01-13 08:40:00 by jwe]
author | jwe |
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date | Thu, 13 Jan 2000 08:40:53 +0000 |
parents | e4f4b2d26ee9 |
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: binomial_rnd (n, p [, r, c]) ## ## binomial_rnd (n, p) returns a matrix of random samples from the ## binomial distribution with parameters n and p. The size of the ## matrix is the common size of n and p. ## ## binomial_rnd (n, p, r, c) returns an r by c matrix of random samples ## from the binomial distribution with parameters n and p. Both n and p ## must be scalar or of size r by c. ## Author: KH <Kurt.Hornik@ci.tuwien.ac.at> ## Description: Random deviates from the binomial distribution function rnd = binomial_rnd (n, p, r, c) if (nargin == 4) if ( !(is_scalar (r) && (r > 0) && (r == round (r))) ) error ("binomial_rnd: r must be a positive integer"); endif if ( !(is_scalar (c) && (c > 0) && (c == round (c))) ) error ("binomial_rnd: c must be a positive integer"); endif [retval, n, p] = common_size (n, p, zeros (r, c)); if (retval > 0) error (strcat("binomial_rnd: ", "n and p must be scalar or of size ", sprintf ("%d by %d", r, c))); endif elseif (nargin == 2) [retval, n, p] = common_size (n, p); if (retval > 0) error ("binomial_rnd: n and p must be of common size or scalar"); endif else usage ("binomial_rnd (n, p [, r, c])"); endif [r, c] = size (n); s = r * c; n = reshape (n, 1, s); p = reshape (p, 1, s); rnd = zeros (1, s); k = find (!(n > 0) | !(n < Inf) | !(n == round (n)) | !(p <= 0) | !(p >= 1)); if any (k) rnd(k) = NaN * ones (1, length (k)); endif k = find ((n > 0) & (n < Inf) & (n == round (n)) & (p >= 0) & (p <= 1)); if any (k) N = max (n(k)); L = length (k); tmp = rand (N, L); ind = (1 : N)' * ones (1, L); rnd(k) = sum ((tmp < ones (N, 1) * p(k)) & (ind <= ones (N, 1) * n(k))); endif rnd = reshape (rnd, r, c); endfunction