--- /dev/null
+## Copyright (C) 2012 Rik Wehbring
+## Copyright (C) 1997-2012 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} {} hygernd (@var{t}, @var{m}, @var{n})
+## @deftypefnx {Function File} {} hygernd (@var{t}, @var{m}, @var{n}, @var{r})
+## @deftypefnx {Function File} {} hygernd (@var{t}, @var{m}, @var{n}, @var{r}, @var{c}, @dots{})
+## @deftypefnx {Function File} {} hygernd (@var{t}, @var{m}, @var{n}, [@var{sz}])
+## Return a matrix of random samples from the hypergeometric distribution
+## with parameters @var{t}, @var{m}, and @var{n}.
+##
+## The parameters @var{t}, @var{m}, and @var{n} must be positive integers
+## with @var{m} and @var{n} not greater than @var{t}.
+##
+## 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{t}, @var{m}, and @var{n}.
+## @end deftypefn
+
+function rnd = hygernd (t, m, n, varargin)
+
+ if (nargin < 3)
+ print_usage ();
+ endif
+
+ if (! isscalar (t) || ! isscalar (m) || ! isscalar (n))
+ [retval, t, m, n] = common_size (t, m, n);
+ if (retval > 0)
+ error ("hygernd: T, M, and N must be of common size or scalars");
+ endif
+ endif
+
+ if (iscomplex (t) || iscomplex (m) || iscomplex (n))
+ error ("hygernd: T, M, and N must not be complex");
+ endif
+
+ if (nargin == 3)
+ sz = size (t);
+ elseif (nargin == 4)
+ 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 ("hygernd: dimension vector must be row vector of non-negative integers");
+ endif
+ elseif (nargin > 4)
+ if (any (cellfun (@(x) (!isscalar (x) || x < 0), varargin)))
+ error ("hygernd: dimensions must be non-negative integers");
+ endif
+ sz = [varargin{:}];
+ endif
+
+ if (!isscalar (t) && !isequal (size (t), sz))
+ error ("hygernd: T, M, and N must be scalar or of size SZ");
+ endif
+
+ if (isa (t, "single") || isa (m, "single") || isa (n, "single"))
+ cls = "single";
+ else
+ cls = "double";
+ endif
+
+ ok = ((t >= 0) & (m >= 0) & (n > 0) & (m <= t) & (n <= t) &
+ (t == fix (t)) & (m == fix (m)) & (n == fix (n)));
+
+ if (isscalar (t))
+ if (ok)
+ v = 0:n;
+ p = hygepdf (v, t, m, n);
+ rnd = v(lookup (cumsum (p(1:end-1)) / sum (p), rand (sz)) + 1);
+ rnd = reshape (rnd, sz);
+ if (strcmp (cls, "single"))
+ rnd = single (rnd);
+ endif
+ else
+ rnd = NaN (sz, cls);
+ endif
+ else
+ rnd = NaN (sz, cls);
+ rn = rand (sz);
+ for i = find (ok(:)') # Must be row vector arg to for loop
+ v = 0 : n(i);
+ p = hygepdf (v, t(i), m(i), n(i));
+ rnd(i) = v(lookup (cumsum (p(1 : end-1)) / sum (p), rn(i)) + 1);
+ endfor
+ endif
+
+endfunction
+
+
+%!assert(size (hygernd (4,2,2)), [1, 1]);
+%!assert(size (hygernd (4*ones(2,1), 2,2)), [2, 1]);
+%!assert(size (hygernd (4*ones(2,2), 2,2)), [2, 2]);
+%!assert(size (hygernd (4, 2*ones(2,1), 2)), [2, 1]);
+%!assert(size (hygernd (4, 2*ones(2,2), 2)), [2, 2]);
+%!assert(size (hygernd (4, 2, 2*ones(2,1))), [2, 1]);
+%!assert(size (hygernd (4, 2, 2*ones(2,2))), [2, 2]);
+%!assert(size (hygernd (4, 2, 2, 3)), [3, 3]);
+%!assert(size (hygernd (4, 2, 2, [4 1])), [4, 1]);
+%!assert(size (hygernd (4, 2, 2, 4, 1)), [4, 1]);
+
+%!assert(class (hygernd (4,2,2)), "double");
+%!assert(class (hygernd (single(4),2,2)), "single");
+%!assert(class (hygernd (single([4 4]),2,2)), "single");
+%!assert(class (hygernd (4,single(2),2)), "single");
+%!assert(class (hygernd (4,single([2 2]),2)), "single");
+%!assert(class (hygernd (4,2,single(2))), "single");
+%!assert(class (hygernd (4,2,single([2 2]))), "single");
+
+%% Test input validation
+%!error hygernd ()
+%!error hygernd (1)
+%!error hygernd (1,2)
+%!error hygernd (ones(3),ones(2),ones(2), 2)
+%!error hygernd (ones(2),ones(3),ones(2), 2)
+%!error hygernd (ones(2),ones(2),ones(3), 2)
+%!error hygernd (i, 2, 2)
+%!error hygernd (2, i, 2)
+%!error hygernd (2, 2, i)
+%!error hygernd (4,2,2, -1)
+%!error hygernd (4,2,2, ones(2))
+%!error hygernd (4,2,2, [2 -1 2])
+%!error hygernd (4*ones(2),2,2, 3)
+%!error hygernd (4*ones(2),2,2, [3, 2])
+%!error hygernd (4*ones(2),2,2, 3, 2)
+
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff