invheat.m

nonlinear eq routines in matlab

function [res] = invheat(lambda)


global A U D V bdelta

n = size(A,2);

% compute regularized solution
w       = diag(D)./(diag(D).^2 + lambda*ones(size(diag(D))));
xlambda = V*(w.*(U(:,1:n)'*bdelta));
res     = norm(bdelta-A*xlambda) - 1.e-3*norm(bdelta);