Mercurial > octave-nkf
view scripts/statistics/distributions/betarnd.m @ 14138:72c96de7a403 stable
maint: update copyright notices for 2012
author | John W. Eaton <jwe@octave.org> |
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date | Mon, 02 Jan 2012 14:25:41 -0500 |
parents | 19b9f17d22af |
children | f3d52523cde1 |
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## 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 ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} betarnd (@var{a}, @var{b}) ## @deftypefnx {Function File} {} betarnd (@var{a}, @var{b}, @var{r}) ## @deftypefnx {Function File} {} betarnd (@var{a}, @var{b}, @var{r}, @var{c}, @dots{}) ## @deftypefnx {Function File} {} betarnd (@var{a}, @var{b}, [@var{sz}]) ## Return a matrix of random samples from the Beta distribution with parameters ## @var{a} and @var{b}. ## ## 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 common size of ## @var{a} and @var{b}. ## @end deftypefn ## Author: KH <Kurt.Hornik@wu-wien.ac.at> ## Description: Random deviates from the Beta distribution function rnd = betarnd (a, b, varargin) if (nargin < 2) print_usage (); endif if (!isscalar (a) || !isscalar (b)) [retval, a, b] = common_size (a, b); if (retval > 0) error ("betarnd: A and B must be of common size or scalars"); endif endif if (iscomplex (a) || iscomplex (b)) error ("betarnd: A and B must not be complex"); endif if (nargin == 2) sz = size (a); elseif (nargin == 3) 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 ("betarnd: dimension vector must be row vector of non-negative integers"); endif elseif (nargin > 3) if (any (cellfun (@(x) (!isscalar (x) || x < 0), varargin))) error ("betarnd: dimensions must be non-negative integers"); endif sz = [varargin{:}]; endif if (!isscalar (a) && !isequal (size (a), sz)) error ("betarnd: A and B must be scalar or of size SZ"); endif if (isa (a, "single") || isa (b, "single")) cls = "single"; else cls = "double"; endif if (isscalar (a) && isscalar (b)) if ((a > 0) && (a < Inf) && (b > 0) && (b < Inf)) r = randg (a, sz); rnd = r ./ (r + randg (b, sz)); if (strcmp (cls, "single")) rnd = single (rnd); endif else rnd = NaN (sz, cls); endif else rnd = NaN (sz, cls); k = (a > 0) & (a < Inf) & (b > 0) & (b < Inf); r = randg (a(k)); rnd(k) = r ./ (r + randg (b(k))); endif endfunction %!assert(size (betarnd (1,2)), [1, 1]); %!assert(size (betarnd (ones(2,1), 2)), [2, 1]); %!assert(size (betarnd (ones(2,2), 2)), [2, 2]); %!assert(size (betarnd (1, 2*ones(2,1))), [2, 1]); %!assert(size (betarnd (1, 2*ones(2,2))), [2, 2]); %!assert(size (betarnd (1, 2, 3)), [3, 3]); %!assert(size (betarnd (1, 2, [4 1])), [4, 1]); %!assert(size (betarnd (1, 2, 4, 1)), [4, 1]); %% Test class of input preserved %!assert(class (betarnd (1, 2)), "double"); %!assert(class (betarnd (single(1), 2)), "single"); %!assert(class (betarnd (single([1 1]), 2)), "single"); %!assert(class (betarnd (1, single(2))), "single"); %!assert(class (betarnd (1, single([2 2]))), "single"); %% Test input validation %!error betarnd () %!error betarnd (1) %!error betarnd (ones(3),ones(2)) %!error betarnd (ones(2),ones(3)) %!error betarnd (i, 2) %!error betarnd (2, i) %!error betarnd (1,2, -1) %!error betarnd (1,2, ones(2)) %!error binornd (1,2, [2 -1 2]) %!error betarnd (1,2, 1, ones(2)) %!error betarnd (1,2, 1, -1) %!error betarnd (ones(2,2), 2, 3) %!error betarnd (ones(2,2), 2, [3, 2]) %!error betarnd (ones(2,2), 2, 2, 3)