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 (c) 1984-98 by The MathWorks, Inc.
%   $Revision: 5.4 $  $Date: 1997/11/21 23:38:57 $

t = sum(diag(a));
