%TRIL Extract lower triangular part.
%   TRIL(X) is the lower triangular part of X.
%   TRIL(X,K) is the elements on and below the K-th diagonal
%   of X .  K = 0 is the main diagonal, K > 0 is above the
%   main diagonal and K < 0 is below the main diagonal.
%
%   See also TRIU, DIAG.

%   Copyright (c) 1984-98 by The MathWorks, Inc.
%   $Revision: 5.5 $  $Date: 1997/11/21 23:30:20 $
%   Built-in function.
