function p3test

n = 100;
alpha = 2*rand(n,  1)-1;
beta  = 2*rand(n-1,1)-1;
B = diag(alpha) + diag(beta,1);
kappa1 = cond(B,inf);
kappa2 = p3cond(alpha, beta);

fprintf('Rel err: %g\n', abs((kappa1-kappa2)/kappa2));
