function t = trace(a)
%TRACE  Sum of diagonal elements.
%   TRACE(A) is the sum of the diagonal elements of A, which is
%   also the sum of the eigenvalues of A.

%   Copyright 1984-2000 The MathWorks, Inc. 
%   $Revision: 5.6 $  $Date: 2000/06/01 02:04:18 $

t = sum(diag(a));
