--- /dev/null
+## 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} {} binornd (@var{n}, @var{p})
+## @deftypefnx {Function File} {} binornd (@var{n}, @var{p}, @var{r})
+## @deftypefnx {Function File} {} binornd (@var{n}, @var{p}, @var{r}, @var{c}, @dots{})
+## @deftypefnx {Function File} {} binornd (@var{n}, @var{p}, [@var{sz}])
+## Return a matrix of random samples from the binomial distribution with
+## parameters @var{n} and @var{p}, where @var{n} is the number of trials
+## and @var{p} is the probability of success.
+##
+## 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{n} and @var{p}.
+## @end deftypefn
+
+## Author: KH <Kurt.Hornik@wu-wien.ac.at>
+## Description: Random deviates from the binomial distribution
+
+function rnd = binornd (n, p, varargin)
+
+ if (nargin < 2)
+ print_usage ();
+ endif
+
+ if (!isscalar (n) || !isscalar (p))
+ [retval, n, p] = common_size (n, p);
+ if (retval > 0)
+ error ("binornd: N and P must be of common size or scalars");
+ endif
+ endif
+
+ if (iscomplex (n) || iscomplex (p))
+ error ("binornd: N and P must not be complex");
+ endif
+
+ if (nargin == 2)
+ sz = size (n);
+ 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 ("binornd: dimension vector must be row vector of non-negative integers");
+ endif
+ elseif (nargin > 3)
+ if (any (cellfun (@(x) (!isscalar (x) || x < 0), varargin)))
+ error ("binornd: dimensions must be non-negative integers");
+ endif
+ sz = [varargin{:}];
+ endif
+
+ if (!isscalar (n) && !isequal (size (n), sz))
+ error ("binornd: N and P must be scalar or of size SZ");
+ endif
+
+ if (isa (n, "single") || isa (p, "single"))
+ cls = "single";
+ else
+ cls = "double";
+ endif
+
+ if (isscalar (n) && isscalar (p))
+ if ((n > 0) && (n < Inf) && (n == fix (n)) && (p >= 0) && (p <= 1))
+ nel = prod (sz);
+ tmp = rand (n, nel);
+ rnd = sum (tmp < p, 1);
+ rnd = reshape (rnd, sz);
+ if (strcmp (cls, "single"))
+ rnd = single (rnd);
+ endif
+ elseif ((n == 0) && (p >= 0) && (p <= 1))
+ rnd = zeros (sz, cls);
+ else
+ rnd = NaN (sz, cls);
+ endif
+ else
+ rnd = zeros (sz, cls);
+
+ k = !(n >= 0) | !(n < Inf) | !(n == fix (n)) | !(p >= 0) | !(p <= 1);
+ rnd(k) = NaN;
+
+ k = (n > 0) & (n < Inf) & (n == fix (n)) & (p >= 0) & (p <= 1);
+ if (any (k(:)))
+ N = max (n(k));
+ L = sum (k(:));
+ tmp = rand (N, L);
+ ind = repmat ((1 : N)', 1, L);
+ rnd(k) = sum ((tmp < repmat (p(k)(:)', N, 1)) &
+ (ind <= repmat (n(k)(:)', N, 1)), 1);
+ endif
+ endif
+
+endfunction
+
+
+%!assert (binornd (0, 0, 1), 0)
+%!assert (binornd ([0, 0], [0, 0], 1, 2), [0, 0])
+
+%!assert(size (binornd (2, 1/2)), [1, 1]);
+%!assert(size (binornd (2*ones(2,1), 1/2)), [2, 1]);
+%!assert(size (binornd (2*ones(2,2), 1/2)), [2, 2]);
+%!assert(size (binornd (2, 1/2*ones(2,1))), [2, 1]);
+%!assert(size (binornd (2, 1/2*ones(2,2))), [2, 2]);
+%!assert(size (binornd (2, 1/2, 3)), [3, 3]);
+%!assert(size (binornd (2, 1/2, [4 1])), [4, 1]);
+%!assert(size (binornd (2, 1/2, 4, 1)), [4, 1]);
+
+%% Test class of input preserved
+%!assert(class (binornd (2, 0.5)), "double");
+%!assert(class (binornd (single(2), 0.5)), "single");
+%!assert(class (binornd (single([2 2]), 0.5)), "single");
+%!assert(class (binornd (2, single(0.5))), "single");
+%!assert(class (binornd (2, single([0.5 0.5]))), "single");
+
+%% Test input validation
+%!error binornd ()
+%!error binornd (1)
+%!error binornd (ones(3),ones(2))
+%!error binornd (ones(2),ones(3))
+%!error binornd (i, 2)
+%!error binornd (2, i)
+%!error binornd (1,2, -1)
+%!error binornd (1,2, ones(2))
+%!error binornd (1,2, [2 -1 2])
+%!error binornd (1,2, 1, ones(2))
+%!error binornd (1,2, 1, -1)
+%!error binornd (ones(2,2), 2, 3)
+%!error binornd (ones(2,2), 2, [3, 2])
+%!error binornd (ones(2,2), 2, 2, 3)
+
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff