Mercurial > jwe > octave
view scripts/statistics/distributions/discrete_pdf.m @ 11156:83da69c6e7be
Sort values in discrete_pdf before calling lookup
author | David Bateman <dbateman@free.fr> |
---|---|
date | Mon, 25 Oct 2010 21:36:29 +0200 |
parents | 1c6ff93c025a |
children | 1740012184f9 |
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## Copyright (C) 1996, 1997, 1998, 2000, 2002, 2004, 2005, 2006, 2007 ## 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} {} discrete_pdf (@var{x}, @var{v}, @var{p}) ## For each element of @var{x}, compute the probability density function ## (PDF) at @var{x} of a univariate discrete distribution which assumes ## the values in @var{v} with probabilities @var{p}. ## @end deftypefn ## Author: KH <Kurt.Hornik@wu-wien.ac.at> ## Description: pDF of a discrete distribution function pdf = discrete_pdf (x, v, p) if (nargin != 3) print_usage (); endif sz = size (x); if (! isvector (v)) error ("discrete_pdf: v must be a vector"); elseif (! isvector (p) || (length (p) != length (v))) error ("discrete_pdf: p must be a vector with length (v) elements"); elseif (! (all (p >= 0) && any (p))) error ("discrete_pdf: p must be a nonzero, nonnegative vector"); endif n = numel (x); m = length (v); x = reshape (x, n, 1); v = reshape (v, 1, m); p = reshape (p / sum (p), m, 1); pdf = NaN (sz); k = find (!isnan (x)); if (any (k)) n = length (k); [vs, vi] = sort (v); pdf (k) = p (vi(lookup (vs, x(k), 'm'))); endif endfunction