X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fstatistics-1.1.3%2Fbinostat.m;fp=octave_packages%2Fstatistics-1.1.3%2Fbinostat.m;h=44a0e83a1e52229f562c66a30878a9e7ee876d6b;hp=0000000000000000000000000000000000000000;hb=c880e8788dfc484bf23ce13fa2787f2c6bca4863;hpb=1705066eceaaea976f010f669ce8e972f3734b05 diff --git a/octave_packages/statistics-1.1.3/binostat.m b/octave_packages/statistics-1.1.3/binostat.m new file mode 100644 index 0000000..44a0e83 --- /dev/null +++ b/octave_packages/statistics-1.1.3/binostat.m @@ -0,0 +1,123 @@ +## 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{m}, @var{v}] =} binostat (@var{n}, @var{p}) +## Compute mean and variance of the binomial distribution. +## +## @subheading Arguments +## +## @itemize @bullet +## @item +## @var{n} is the first parameter of the binomial distribution. The elements +## of @var{n} must be natural numbers +## +## @item +## @var{p} is the second parameter of the binomial distribution. The +## elements of @var{p} must be probabilities +## @end itemize +## @var{n} and @var{p} must be of common size or one of them must be scalar +## +## @subheading Return values +## +## @itemize @bullet +## @item +## @var{m} is the mean of the binomial distribution +## +## @item +## @var{v} is the variance of the binomial distribution +## @end itemize +## +## @subheading Examples +## +## @example +## @group +## n = 1:6; +## p = 0:0.2:1; +## [m, v] = binostat (n, p) +## @end group +## +## @group +## [m, v] = binostat (n, 0.5) +## @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 binomial distribution + +function [m, v] = binostat (n, p) + + # Check arguments + if (nargin != 2) + print_usage (); + endif + + if (! isempty (n) && ! ismatrix (n)) + error ("binostat: n must be a numeric matrix"); + endif + if (! isempty (p) && ! ismatrix (p)) + error ("binostat: p must be a numeric matrix"); + endif + + if (! isscalar (n) || ! isscalar (p)) + [retval, n, p] = common_size (n, p); + if (retval > 0) + error ("binostat: n and p must be of common size or scalar"); + endif + endif + + # Calculate moments + m = n .* p; + v = n .* p .* (1 - p); + + # Continue argument check + k = find (! (n > 0) | ! (n < Inf) | ! (n == round (n)) | ! (p >= 0) | ! (p <= 1)); + if (any (k)) + m(k) = NaN; + v(k) = NaN; + endif + +endfunction + +%!test +%! n = 1:6; +%! p = 0:0.2:1; +%! [m, v] = binostat (n, p); +%! expected_m = [0.00, 0.40, 1.20, 2.40, 4.00, 6.00]; +%! expected_v = [0.00, 0.32, 0.72, 0.96, 0.80, 0.00]; +%! assert (m, expected_m, 0.001); +%! assert (v, expected_v, 0.001); + +%!test +%! n = 1:6; +%! [m, v] = binostat (n, 0.5); +%! expected_m = [0.50, 1.00, 1.50, 2.00, 2.50, 3.00]; +%! expected_v = [0.25, 0.50, 0.75, 1.00, 1.25, 1.50]; +%! assert (m, expected_m, 0.001); +%! assert (v, expected_v, 0.001);