function siz = size(a,idx)
%SIZE Return size of sptenmat.
%  
%   D = SIZE(T) returns the size of the tensor.  
%
%   I = size(T,DIM) returns the sizes of the dimensions specified by DIM.
%
%   See also SPTENMAT.
%
%MATLAB Tensor Toolbox.
%Copyright 2012, Sandia Corporation.

% This is the MATLAB Tensor Toolbox by T. Kolda, B. Bader, and others.
% http://www.sandia.gov/~tgkolda/TensorToolbox.
% Copyright (2012) Sandia Corporation. Under the terms of Contract
% DE-AC04-94AL85000, there is a non-exclusive license for use of this
% work by or on behalf of the U.S. Government. Export of this data may
% require a license from the United States Government.
% The full license terms can be found in the file LICENSE.txt


if isempty(a.tsize)
    siz = [];
    return;
end

m = prod(a.tsize(a.rdims));
n = prod(a.tsize(a.cdims));
siz = [m n];

if  exist('idx','var')
    siz = siz(idx);
end
