clear all
close all

A = mmread('a_shell.mtx');
disp('loaded matrix A');

D = spfun(@(x) 1./x,diag(diag(A)));

L = tril(A,-1);
I = speye(size(A));

M = (I-L*D+(L*D)^2)*D*(I-D*(L')+(D*(L'))^2);

condA = condest(A)
% condMA = condest(M*A)