load Erdos991

A = Problem.A

tic
[v,d]=eigs(A);
toc

tic
[v2,d2]=eigs(A - 50*speye(size(A)));
toc

d = d2 + 50*eye(size(d2))

tic
[v3,d3]=eigs(A,6,'sa');
toc

[d,d3]
