X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fstatistics-1.1.3%2Fhygestat.m;fp=octave_packages%2Fstatistics-1.1.3%2Fhygestat.m;h=54d3caa03a742af57006d8f8ef1887701a8cd52a;hp=0000000000000000000000000000000000000000;hb=c880e8788dfc484bf23ce13fa2787f2c6bca4863;hpb=1705066eceaaea976f010f669ce8e972f3734b05 diff --git a/octave_packages/statistics-1.1.3/hygestat.m b/octave_packages/statistics-1.1.3/hygestat.m new file mode 100644 index 0000000..54d3caa --- /dev/null +++ b/octave_packages/statistics-1.1.3/hygestat.m @@ -0,0 +1,133 @@ +## Copyright (C) 2006, 2007 Arno Onken +## +## 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 3 of the License, 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 program; if not, see . + +## -*- texinfo -*- +## @deftypefn {Function File} {[@var{mn}, @var{v}] =} hygestat (@var{t}, @var{m}, @var{n}) +## Compute mean and variance of the hypergeometric distribution. +## +## @subheading Arguments +## +## @itemize @bullet +## @item +## @var{t} is the total size of the population of the hypergeometric +## distribution. The elements of @var{t} must be positive natural numbers +## +## @item +## @var{m} is the number of marked items of the hypergeometric distribution. +## The elements of @var{m} must be natural numbers +## +## @item +## @var{n} is the size of the drawn sample of the hypergeometric +## distribution. The elements of @var{n} must be positive natural numbers +## @end itemize +## @var{t}, @var{m}, and @var{n} must be of common size or scalar +## +## @subheading Return values +## +## @itemize @bullet +## @item +## @var{mn} is the mean of the hypergeometric distribution +## +## @item +## @var{v} is the variance of the hypergeometric distribution +## @end itemize +## +## @subheading Examples +## +## @example +## @group +## t = 4:9; +## m = 0:5; +## n = 1:6; +## [mn, v] = hygestat (t, m, n) +## @end group +## +## @group +## [mn, v] = hygestat (t, m, 2) +## @end group +## @end example +## +## @subheading References +## +## @enumerate +## @item +## Wendy L. Martinez and Angel R. Martinez. @cite{Computational Statistics +## Handbook with MATLAB}. Appendix E, pages 547-557, Chapman & Hall/CRC, +## 2001. +## +## @item +## Athanasios Papoulis. @cite{Probability, Random Variables, and Stochastic +## Processes}. McGraw-Hill, New York, second edition, 1984. +## @end enumerate +## @end deftypefn + +## Author: Arno Onken +## Description: Moments of the hypergeometric distribution + +function [mn, v] = hygestat (t, m, n) + + # Check arguments + if (nargin != 3) + print_usage (); + endif + + if (! isempty (t) && ! ismatrix (t)) + error ("hygestat: t must be a numeric matrix"); + endif + if (! isempty (m) && ! ismatrix (m)) + error ("hygestat: m must be a numeric matrix"); + endif + if (! isempty (n) && ! ismatrix (n)) + error ("hygestat: n must be a numeric matrix"); + endif + + if (! isscalar (t) || ! isscalar (m) || ! isscalar (n)) + [retval, t, m, n] = common_size (t, m, n); + if (retval > 0) + error ("hygestat: t, m and n must be of common size or scalar"); + endif + endif + + # Calculate moments + mn = (n .* m) ./ t; + v = (n .* (m ./ t) .* (1 - m ./ t) .* (t - n)) ./ (t - 1); + + # Continue argument check + k = find (! (t >= 0) | ! (m >= 0) | ! (n > 0) | ! (t == round (t)) | ! (m == round (m)) | ! (n == round (n)) | ! (m <= t) | ! (n <= t)); + if (any (k)) + mn(k) = NaN; + v(k) = NaN; + endif + +endfunction + +%!test +%! t = 4:9; +%! m = 0:5; +%! n = 1:6; +%! [mn, v] = hygestat (t, m, n); +%! expected_mn = [0.0000, 0.4000, 1.0000, 1.7143, 2.5000, 3.3333]; +%! expected_v = [0.0000, 0.2400, 0.4000, 0.4898, 0.5357, 0.5556]; +%! assert (mn, expected_mn, 0.001); +%! assert (v, expected_v, 0.001); + +%!test +%! t = 4:9; +%! m = 0:5; +%! [mn, v] = hygestat (t, m, 2); +%! expected_mn = [0.0000, 0.4000, 0.6667, 0.8571, 1.0000, 1.1111]; +%! expected_v = [0.0000, 0.2400, 0.3556, 0.4082, 0.4286, 0.4321]; +%! assert (mn, expected_mn, 0.001); +%! assert (v, expected_v, 0.001);