--- /dev/null
+## Copyright (C) 2009, 2011 Lukas F. Reichlin
+##
+## This file is part of LTI Syncope.
+##
+## LTI Syncope 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.
+##
+## LTI Syncope 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 LTI Syncope. If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{nvec} =} size (@var{sys})
+## @deftypefnx {Function File} {@var{n} =} size (@var{sys}, @var{dim})
+## @deftypefnx {Function File} {[@var{p}, @var{m}] =} size (@var{sys})
+## LTI model size, i.e. number of outputs and inputs.
+##
+## @strong{Inputs}
+## @table @var
+## @item sys
+## LTI system.
+## @item dim
+## If given a second argument, @command{size} will return the size of the
+## corresponding dimension.
+## @end table
+##
+## @strong{Outputs}
+## @table @var
+## @item nvec
+## Row vector. The first element is the number of outputs (rows) and the second
+## element the number of inputs (columns).
+## @item n
+## Scalar value. The size of the dimension @var{dim}.
+## @item p
+## Number of outputs.
+## @item m
+## Number of inputs.
+## @end table
+## @end deftypefn
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: September 2009
+## Version: 0.2
+
+function [n, varargout] = size (sys, dim = 0)
+
+ if (nargin > 2)
+ print_usage ();
+ endif
+
+ p = numel (sys.outname); # WARNING: system matrices may change without
+ m = numel (sys.inname); # being noticed by the i/o names!
+
+ switch (dim)
+ case 0
+ switch (nargout)
+ case 0
+ if (p == 1)
+ stry = "";
+ else
+ stry = "s";
+ endif
+ if (m == 1)
+ stru = "";
+ else
+ stru = "s";
+ endif
+ disp (sprintf ("LTI model with %d output%s and %d input%s.", p, stry, m, stru));
+ case 1
+ n = [p, m];
+ case 2
+ n = p;
+ varargout{1} = m;
+ otherwise
+ print_usage ();
+ endswitch
+ case 1
+ n = p;
+ case 2
+ n = m;
+ otherwise
+ print_usage ();
+ endswitch
+
+endfunction