X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fm%2Fstatistics%2Fdistributions%2Fgeornd.m;fp=octave_packages%2Fm%2Fstatistics%2Fdistributions%2Fgeornd.m;h=d2c7f25b77b435b80ea4f42b2e48fd4520edb44c;hp=0000000000000000000000000000000000000000;hb=1c0469ada9531828709108a4882a751d2816994a;hpb=63de9f36673d49121015e3695f2c336ea92bc278 diff --git a/octave_packages/m/statistics/distributions/geornd.m b/octave_packages/m/statistics/distributions/geornd.m new file mode 100644 index 0000000..d2c7f25 --- /dev/null +++ b/octave_packages/m/statistics/distributions/geornd.m @@ -0,0 +1,125 @@ +## 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} {} geornd (@var{p}) +## @deftypefnx {Function File} {} geornd (@var{p}, @var{r}) +## @deftypefnx {Function File} {} geornd (@var{p}, @var{r}, @var{c}, @dots{}) +## @deftypefnx {Function File} {} geornd (@var{p}, [@var{sz}]) +## Return a matrix of random samples from the geometric distribution with +## parameter @var{p}. +## +## When called with a single size argument, return a square matrix with +## the dimension specified. When called with more than one scalar argument the +## first two arguments are taken as the number of rows and columns and any +## further arguments specify additional matrix dimensions. The size may also +## be specified with a vector of dimensions @var{sz}. +## +## If no size arguments are given then the result matrix is the size of +## @var{p}. +## @end deftypefn + +## Author: KH +## Description: Random deviates from the geometric distribution + +function rnd = geornd (p, varargin) + + if (nargin < 1) + print_usage (); + endif + + if (nargin == 1) + sz = size (p); + elseif (nargin == 2) + if (isscalar (varargin{1}) && varargin{1} >= 0) + sz = [varargin{1}, varargin{1}]; + elseif (isrow (varargin{1}) && all (varargin{1} >= 0)) + sz = varargin{1}; + else + error ("geornd: dimension vector must be row vector of non-negative integers"); + endif + elseif (nargin > 2) + if (any (cellfun (@(x) (!isscalar (x) || x < 0), varargin))) + error ("geornd: dimensions must be non-negative integers"); + endif + sz = [varargin{:}]; + endif + + if (!isscalar (p) && !isequal (size (p), sz)) + error ("geornd: P must be scalar or of size SZ"); + endif + + if (iscomplex (p)) + error ("geornd: P must not be complex"); + endif + + if (isa (p, "single")) + cls = "single"; + else + cls = "double"; + endif + + if (isscalar (p)) + if (p > 0 && p < 1); + rnd = floor (- rande (sz) ./ log (1 - p)); + elseif (p == 0) + rnd = Inf (sz, cls); + elseif (p == 1) + rnd = zeros (sz, cls); + elseif (p < 0 || p > 1) + rnd = NaN (sz, cls); + endif + else + rnd = floor (- rande (sz) ./ log (1 - p)); + + k = !(p >= 0) | !(p <= 1); + rnd(k) = NaN; + + k = (p == 0); + rnd(k) = Inf; + endif + +endfunction + + +%!assert(size (geornd (0.5)), [1, 1]); +%!assert(size (geornd (0.5*ones(2,1))), [2, 1]); +%!assert(size (geornd (0.5*ones(2,2))), [2, 2]); +%!assert(size (geornd (0.5, 3)), [3, 3]); +%!assert(size (geornd (0.5, [4 1])), [4, 1]); +%!assert(size (geornd (0.5, 4, 1)), [4, 1]); + +%% Test class of input preserved +%!assert(class (geornd (0.5)), "double"); +%!assert(class (geornd (single(0.5))), "single"); +%!assert(class (geornd (single([0.5 0.5]))), "single"); +%!assert(class (geornd (single(0))), "single"); +%!assert(class (geornd (single(1))), "single"); + +%% Test input validation +%!error geornd () +%!error geornd (ones(3),ones(2)) +%!error geornd (ones(2),ones(3)) +%!error geornd (i) +%!error geornd (1, -1) +%!error geornd (1, ones(2)) +%!error geornd (1, [2 -1 2]) +%!error geornd (ones(2,2), 2, 3) +%!error geornd (ones(2,2), 3, 2) +