--- /dev/null
+## Copyright (C) 2008 Sylvain Pelissier <sylvain.pelissier@gmail.com>
+##
+## 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} {@var{intrlvd} =} intrlv (@var{data}, @var{elements})
+## Interleaved elements of @var{data} according to @var{elements}.
+## @seealso{deintrlv}
+## @end deftypefn
+
+function intrlvd = intrlv(data,elements)
+ if(nargin < 2 || nargin >2)
+ error('usage : interlvd = interlv(data,elements)');
+ end
+
+ if(~isvector(elements))
+ error("Elements must be a vector");
+ end
+
+ if(isvector(data))
+ if(length(elements) ~= length(data) || any(sort(elements) ~= 1:length(data)))
+ error("elements must be a permutation of data indices");
+ end
+ intrlvd = data(elements);
+ else
+ if(length(elements) ~= size(data,1) || any(sort(elements) ~= 1:size(data,1)))
+ error("elements must be a permutation of data indices");
+ end
+ intrlvd = data(elements,:);
+ end