Mercurial > octave-nkf
view scripts/statistics/distributions/exprnd.m @ 14683:57569a35765c
Simplify class handling ('single' vs. 'double') for statistical distribution random functions.
* betarnd.m, cauchy_rnd.m, chi2rnd.m, exprnd.m, frnd.m, gamrnd.m, geornd.m,
lognrnd.m, nbinrnd.m, normrnd.m, poissrnd.m, trnd.m, unidrnd.m, unifrnd.m,
wblrnd.m: Use class argument to random number function rather than explicitly
or implicitly casting output to class single.
author | Rik <octave@nomad.inbox5.com> |
---|---|
date | Thu, 24 May 2012 09:50:28 -0700 |
parents | f3d52523cde1 |
children | d63878346099 |
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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} {} exprnd (@var{lambda}) ## @deftypefnx {Function File} {} exprnd (@var{lambda}, @var{r}) ## @deftypefnx {Function File} {} exprnd (@var{lambda}, @var{r}, @var{c}, @dots{}) ## @deftypefnx {Function File} {} exprnd (@var{lambda}, [@var{sz}]) ## Return a matrix of random samples from the exponential distribution with ## mean @var{lambda}. ## ## 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{lambda}. ## @end deftypefn ## Author: KH <Kurt.Hornik@wu-wien.ac.at> ## Description: Random deviates from the exponential distribution function rnd = exprnd (lambda, varargin) if (nargin < 1) print_usage (); endif if (nargin == 1) sz = size (lambda); 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 ("exprnd: dimension vector must be row vector of non-negative integers"); endif elseif (nargin > 2) if (any (cellfun (@(x) (!isscalar (x) || x < 0), varargin))) error ("exprnd: dimensions must be non-negative integers"); endif sz = [varargin{:}]; endif if (!isscalar (lambda) && !isequal (size (lambda), sz)) error ("exprnd: LAMBDA must be scalar or of size SZ"); endif if (iscomplex (lambda)) error ("exprnd: LAMBDA must not be complex"); endif if (isa (lambda, "single")) cls = "single"; else cls = "double"; endif if (isscalar (lambda)) if ((lambda > 0) && (lambda < Inf)) rnd = rande (sz, cls) * lambda; else rnd = NaN (sz, cls); endif else rnd = NaN (sz, cls); k = (lambda > 0) & (lambda < Inf); rnd(k) = rande (sum (k(:)), 1, cls) .* lambda(k)(:); endif endfunction %!assert (size (exprnd (2)), [1, 1]) %!assert (size (exprnd (ones (2,1))), [2, 1]) %!assert (size (exprnd (ones (2,2))), [2, 2]) %!assert (size (exprnd (1, 3)), [3, 3]) %!assert (size (exprnd (1, [4 1])), [4, 1]) %!assert (size (exprnd (1, 4, 1)), [4, 1]) %% Test class of input preserved %!assert (class (exprnd (1)), "double") %!assert (class (exprnd (single (1))), "single") %!assert (class (exprnd (single ([1 1]))), "single") %% Test input validation %!error exprnd () %!error exprnd (1, -1) %!error exprnd (1, ones (2)) %!error exprnd (i) %!error exprnd (1, [2 -1 2]) %!error exprnd (1, 2, -1) %!error exprnd (1, 2, ones (2)) %!error exprnd (ones (2,2), 3) %!error exprnd (ones (2,2), [3, 2]) %!error exprnd (ones (2,2), 2, 3)