function n = numel(df, varargin)
%# function resu = end(df, varargin)
%# This is the numel operator for a dataframe object, returning the
%# product of the number of rows by the number of columns
%% Copyright (C) 2009-2010 Pascal Dupuis <Pascal.Dupuis@uclouvain.be>
%% 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 2, 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
%% You should have received a copy of the GNU General Public
%% License along with Octave; see the file COPYING. If not,
%% write to the Free Software Foundation, 59 Temple Place -
%% Suite 330, Boston, MA 02111-1307, USA.
%# $Id: numel.m 981 2010-07-26 16:23:08Z dupuis $
if 1 == nargin,
n = prod(df._cnt([1 end]));
function usage = print_usage()
usage = strcat('Invalid call to numel. Correct usage is: ', ' ', ...
'-- Overloaded Function: numel (A)');