X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=octave_packages%2Fm%2Fstatistics%2Fdistributions%2Fbetacdf.m;fp=octave_packages%2Fm%2Fstatistics%2Fdistributions%2Fbetacdf.m;h=59c41ae5427bacd36c8ef7b4f4108ae810aad80a;hb=1c0469ada9531828709108a4882a751d2816994a;hp=0000000000000000000000000000000000000000;hpb=63de9f36673d49121015e3695f2c336ea92bc278;p=CreaPhase.git diff --git a/octave_packages/m/statistics/distributions/betacdf.m b/octave_packages/m/statistics/distributions/betacdf.m new file mode 100644 index 0000000..59c41ae --- /dev/null +++ b/octave_packages/m/statistics/distributions/betacdf.m @@ -0,0 +1,93 @@ +## Copyright (C) 2012 Rik Wehbring +## Copyright (C) 1995-2012 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 +## . + +## -*- texinfo -*- +## @deftypefn {Function File} {} betacdf (@var{x}, @var{a}, @var{b}) +## For each element of @var{x}, compute the cumulative distribution function +## (CDF) at @var{x} of the Beta distribution with parameters @var{a} and +## @var{b}. +## @end deftypefn + +## Author: KH +## Description: CDF of the Beta distribution + +function cdf = betacdf (x, a, b) + + if (nargin != 3) + print_usage (); + endif + + if (!isscalar (a) || !isscalar (b)) + [retval, x, a, b] = common_size (x, a, b); + if (retval > 0) + error ("betacdf: X, A, and B must be of common size or scalars"); + endif + endif + + if (iscomplex (x) || iscomplex (a) || iscomplex (b)) + error ("betacdf: X, A, and B must not be complex"); + endif + + if (isa (x, "single") || isa (a, "single") || isa (b, "single")) + cdf = zeros (size (x), "single"); + else + cdf = zeros (size (x)); + endif + + k = isnan (x) | !(a > 0) | !(b > 0); + cdf(k) = NaN; + + k = (x >= 1) & (a > 0) & (b > 0); + cdf(k) = 1; + + k = (x > 0) & (x < 1) & (a > 0) & (b > 0); + if (isscalar (a) && isscalar (b)) + cdf(k) = betainc (x(k), a, b); + else + cdf(k) = betainc (x(k), a(k), b(k)); + endif + +endfunction + + +%!shared x,y +%! x = [-1 0 0.5 1 2]; +%! y = [0 0 0.75 1 1]; +%!assert(betacdf (x, ones(1,5), 2*ones(1,5)), y); +%!assert(betacdf (x, 1, 2*ones(1,5)), y); +%!assert(betacdf (x, ones(1,5), 2), y); +%!assert(betacdf (x, [0 1 NaN 1 1], 2), [NaN 0 NaN 1 1]); +%!assert(betacdf (x, 1, 2*[0 1 NaN 1 1]), [NaN 0 NaN 1 1]); +%!assert(betacdf ([x(1:2) NaN x(4:5)], 1, 2), [y(1:2) NaN y(4:5)]); + +%% Test class of input preserved +%!assert(betacdf ([x, NaN], 1, 2), [y, NaN]); +%!assert(betacdf (single([x, NaN]), 1, 2), single([y, NaN])); +%!assert(betacdf ([x, NaN], single(1), 2), single([y, NaN])); +%!assert(betacdf ([x, NaN], 1, single(2)), single([y, NaN])); + +%% Test input validation +%!error betacdf () +%!error betacdf (1) +%!error betacdf (1,2) +%!error betacdf (1,2,3,4) +%!error betacdf (ones(3),ones(2),ones(2)) +%!error betacdf (ones(2),ones(3),ones(2)) +%!error betacdf (ones(2),ones(2),ones(3)) +