CalcDelta

function delta = CalcDelta(U, x, y)

P = zeros(3, 3);
Q = zeros(3, 1);
t = 0.2;

for i = 1:251
    cur = U(:,:,i);
    P = P + t * (cur' * cur);
    Q = Q + t * (cur' * (y(:,i) - x(:,i)));
end;

delta = inv(P) * Q;

end