sigma = [1/sqrt(2) 1/4]; nrm = 0*sigma;
Z=inline('sigma*(cosh(t)-i*sinh(t))','t','sigma');
tol = 1e-16;  T = log(1/tol)^(1/3); table=[];
for h = [16 8 4 2 1]*0.04;
    for p=1:2
        m = floor(T/h);
        k = -m:0; tau = kron(k,[1 -1])*h; t = tau + tau.^3/3;
        c = Z(t,sigma(p)); dz = -i*conj(c).*(1+tau.^2);
        w = h*cot(pi*c).*dz/2/i; w(end)=[]; c(end)=[];
        n = length(w);
        A = zeros(n,n);
        for j=1:n
            for k=1:n
                A(j,k) = sqrt(w(j))*sqrt(w(k))/...
                    ((c(j)+c(k)-1)*(c(j)+c(k))/2-(c(k)-1));
            end
        end
        nrm(p) = real(sqrt(max(eig(A.'*A))));
    end
    table = [table; h n nrm];
end
table