function Z = newton(F, dF, Z0, atol, maxiter) Z = Z0; theta = 0.5; i = 1; Delta = - dF(Z) \ F(Z); Z = Z + Delta; while norm(Delta)*theta/(1-theta) > atol && i < maxiter Delta_old = Delta; Delta = - dF(Z) \ F(Z); Z = Z + Delta; theta = norm(Delta)/norm(Delta_old); i = i+1; end end