The analytic solutions for the vectors of the parameters g and l are seemingly hard to obtain. They need to be solved by numerical methods, such as Gradient-Descent (GD) method, Davidson Fletcher-Powell (DFP) method and Broyden-Fletcher-Goldfarb-Smith (BFGS) method. As the estimations of b and S are the functions of g and l and dependent on each other, an iterative scheme is required to obtain the estimations of q ¼ [g, b0 , l, S]. Here we present an iterative ML method to estimate these unknown parameters. If we first assume l ¼ 0 and S ¼ IT, then we can calculateb ∧ as