1 ## Copyright (C) 2012 Rik Wehbring
2 ## Copyright (C) 2005-2012 John W. Eaton
4 ## This file is part of Octave.
6 ## Octave is free software; you can redistribute it and/or modify it
7 ## under the terms of the GNU General Public License as published by
8 ## the Free Software Foundation; either version 3 of the License, or (at
9 ## your option) any later version.
11 ## Octave is distributed in the hope that it will be useful, but
12 ## WITHOUT ANY WARRANTY; without even the implied warranty of
13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 ## General Public License for more details.
16 ## You should have received a copy of the GNU General Public License
17 ## along with Octave; see the file COPYING. If not, see
18 ## <http://www.gnu.org/licenses/>.
21 ## @deftypefn {Function File} {} unidrnd (@var{n})
22 ## @deftypefnx {Function File} {} unidrnd (@var{n}, @var{r})
23 ## @deftypefnx {Function File} {} unidrnd (@var{n}, @var{r}, @var{c}, @dots{})
24 ## @deftypefnx {Function File} {} unidrnd (@var{n}, [@var{sz}])
25 ## Return a matrix of random samples from the discrete uniform distribution
26 ## which assumes the integer values 1--@var{n} with equal probability.
27 ## @var{n} may be a scalar or a multi-dimensional array.
29 ## When called with a single size argument, return a square matrix with
30 ## the dimension specified. When called with more than one scalar argument the
31 ## first two arguments are taken as the number of rows and columns and any
32 ## further arguments specify additional matrix dimensions. The size may also
33 ## be specified with a vector of dimensions @var{sz}.
35 ## If no size arguments are given then the result matrix is the size of
41 function rnd = unidrnd (n, varargin)
50 if (isscalar (varargin{1}) && varargin{1} >= 0)
51 sz = [varargin{1}, varargin{1}];
52 elseif (isrow (varargin{1}) && all (varargin{1} >= 0))
55 error ("unidrnd: dimension vector must be row vector of non-negative integers");
58 if (any (cellfun (@(x) (!isscalar (x) || x < 0), varargin)))
59 error ("unidrnd: dimensions must be non-negative integers");
64 if (!isscalar (n) && !isequal (size (n), sz))
65 error ("unidrnd: N must be scalar or of size SZ");
69 error ("unidrnd: N must not be complex");
72 if (isa (n, "single"))
79 if (n > 0 && n == fix (n))
80 rnd = ceil (rand (sz) * n);
85 rnd = ceil (rand (sz) .* n);
87 k = ! (n > 0 & n == fix (n));
94 %!assert(size (unidrnd (2)), [1, 1]);
95 %!assert(size (unidrnd (ones(2,1))), [2, 1]);
96 %!assert(size (unidrnd (ones(2,2))), [2, 2]);
97 %!assert(size (unidrnd (10, [4 1])), [4, 1]);
98 %!assert(size (unidrnd (10, 4, 1)), [4, 1]);
100 %% Test class of input preserved
101 %!assert(class (unidrnd (2)), "double");
102 %!assert(class (unidrnd (single(2))), "single");
103 %!assert(class (unidrnd (single([2 2]))), "single");
105 %% Test input validation
107 %!error unidrnd (10, [1;2;3])
108 %!error unidrnd (10, 2, ones(2))
109 %!error unidrnd (10*ones(2), 2, 1)