X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fm%2Fstatistics%2Fdistributions%2Fwblcdf.m;fp=octave_packages%2Fm%2Fstatistics%2Fdistributions%2Fwblcdf.m;h=dd06bfef9fdab55308a048ef12020a665aebfc15;hp=0000000000000000000000000000000000000000;hb=1c0469ada9531828709108a4882a751d2816994a;hpb=63de9f36673d49121015e3695f2c336ea92bc278 diff --git a/octave_packages/m/statistics/distributions/wblcdf.m b/octave_packages/m/statistics/distributions/wblcdf.m new file mode 100644 index 0000000..dd06bfe --- /dev/null +++ b/octave_packages/m/statistics/distributions/wblcdf.m @@ -0,0 +1,113 @@ +## 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} {} wblcdf (@var{x}) +## @deftypefnx {Function File} {} wblcdf (@var{x}, @var{scale}) +## @deftypefnx {Function File} {} wblcdf (@var{x}, @var{scale}, @var{shape}) +## Compute the cumulative distribution function (CDF) at @var{x} of the +## Weibull distribution with scale parameter @var{scale} and shape +## parameter @var{shape}, which is +## @tex +## $$ 1 - e^{-({x \over scale})^{shape}} $$ +## for $x \geq 0$. +## @end tex +## @ifnottex +## +## @example +## 1 - exp (-(x/scale)^shape) +## @end example +## +## @noindent +## for @var{x} @geq{} 0. +## +## Default values are @var{scale} = 1, @var{shape} = 1. +## @end ifnottex +## @end deftypefn + +## Author: KH +## Description: CDF of the Weibull distribution + +function cdf = wblcdf (x, scale = 1, shape = 1) + + if (nargin < 1 || nargin > 3) + print_usage (); + endif + + if (!isscalar (shape) || !isscalar (scale)) + [retval, x, shape, scale] = common_size (x, shape, scale); + if (retval > 0) + error ("wblcdf: X, SCALE, and SHAPE must be of common size or scalars"); + endif + endif + + if (iscomplex (x) || iscomplex (scale) || iscomplex (shape)) + error ("wblcdf: X, SCALE, and SHAPE must not be complex"); + endif + + if (isa (x, "single") || isa (scale, "single") || isa (shape, "single")) + cdf = NaN (size (x), "single"); + else + cdf = NaN (size (x)); + endif + + ok = (shape > 0) & (shape < Inf) & (scale > 0) & (scale < Inf); + + k = (x <= 0) & ok; + cdf(k) = 0; + + k = (x == Inf) & ok; + cdf(k) = 1; + + k = (x > 0) & (x < Inf) & ok; + if (isscalar (shape) && isscalar (scale)) + cdf(k) = 1 - exp (- (x(k) / scale) .^ shape); + else + cdf(k) = 1 - exp (- (x(k) ./ scale(k)) .^ shape(k)); + endif + +endfunction + + +%!shared x,y +%! x = [-1 0 0.5 1 Inf]; +%! y = [0, 1-exp(-x(2:4)), 1]; +%!assert(wblcdf (x, ones(1,5), ones(1,5)), y); +%!assert(wblcdf (x, 1, ones(1,5)), y); +%!assert(wblcdf (x, ones(1,5), 1), y); +%!assert(wblcdf (x, [0 1 NaN Inf 1], 1), [NaN 0 NaN NaN 1]); +%!assert(wblcdf (x, 1, [0 1 NaN Inf 1]), [NaN 0 NaN NaN 1]); +%!assert(wblcdf ([x(1:2) NaN x(4:5)], 1, 1), [y(1:2) NaN y(4:5)]); + +%% Test class of input preserved +%!assert(wblcdf ([x, NaN], 1, 1), [y, NaN]); +%!assert(wblcdf (single([x, NaN]), 1, 1), single([y, NaN])); +%!assert(wblcdf ([x, NaN], single(1), 1), single([y, NaN])); +%!assert(wblcdf ([x, NaN], 1, single(1)), single([y, NaN])); + +%% Test input validation +%!error wblcdf () +%!error wblcdf (1,2,3,4) +%!error wblcdf (ones(3),ones(2),ones(2)) +%!error wblcdf (ones(2),ones(3),ones(2)) +%!error wblcdf (ones(2),ones(2),ones(3)) +%!error wblcdf (i, 2, 2) +%!error wblcdf (2, i, 2) +%!error wblcdf (2, 2, i) +