Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / linear-algebra-2.2.0 / cartprod.m

diff --git a/octave_packages/linear-algebra-2.2.0/cartprod.m b/octave_packages/linear-algebra-2.2.0/cartprod.m
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+## Copyright (C) 2008 Muthiah Annamalai <muthiah.annamalai@uta.edu>
+## Copyright (C) 2010 VZLU Prague
+##
+## This program 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.
+##
+## This program 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
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} cartprod (@var{varargin})
+##
+## Computes the cartesian product of given column vectors ( row vectors ).
+## The vector elements are assumend to be numbers.
+##
+## Alternatively the vectors can be specified by as a matrix, by its columns.
+##
+## To calculate the cartesian product of vectors,
+## P = A x B x C x D ... . Requires A, B, C, D be column vectors.
+## The algorithm is iteratively calcualte the products,
+##  ( ( (A x B ) x C ) x D ) x  etc.
+##
+## @example
+## @group
+##   cartprod(1:2,3:4,0:1)
+##   ans =   1   3   0
+##           2   3   0
+##           1   4   0
+##           2   4   0
+##           1   3   1
+##           2   3   1
+##           1   4   1
+##           2   4   1
+## @end group
+## @end example
+## @end deftypefn
+## @seealso{kron}
+
+function p = cartprod (varargin)
+   if (nargin < 1)
+     print_usage ();
+   elseif (nargin == 1)
+     p = varargin{1};
+   endif
+
+   [p{1:nargin}] = ndgrid (varargin{:});
+   p = cat (nargin+1, p{:});
+   p = reshape (p, [], nargin);
+
+endfunction
+
+%!assert(cartprod(1:2,0:1),[1 0; 2 0; 1 1; 2 1])