issymmetric.m

国外专家做的求解LMI鲁棒控制的工具箱,可以相对高效的解决LMI问题

function issym=issymmetric(X)
%ISSYMMETRIC Check if variable is symmetric

% Author Johan L鰂berg 
% $Id: issymmetric.m,v 1.4 2005/04/14 10:27:09 joloef Exp $  

n = X.n;
m = X.m;
if (n==m)
    % What are the linar indicies to the transposed matrices
    ind = reshape(reshape(1:n^2,n,n)',n^2,1);
    issym = norm(X.basis-X.basis(ind,:),1)<1e-10;   
else
    issym = 0;
end