MATLAB FINANCIAL DERIVATIVES TOOLBOX Manual de usuario Pagina 107

  • Descarga
  • Añadir a mis manuales
  • Imprimir
  • Pagina
    / 119
  • Tabla de contenidos
  • MARCADORES
  • Valorado. / 5. Basado en revisión del cliente
Vista de pagina 106
106
stable convergence but with extremely slow rate. Typical values of a
range between 0.01 and 0.15 depending on the faced problem.
Specifically, )x('f for a function with n variables is:
=
n
x
)x(f
x
)x(f
x
)x(f
)x('f L
21
Step #3: Increase: k
k+1 and if the current iteration index k is larger
than the maximum number of iterations or if )x('af
k
<e then stop and
return
k
x , otherwise go to Step #2 and perform one more iteration of
the algorithm (the e is the desire accuracy, usually set to a small
quantity such as 1e-6, whereas the maximum number of iterations
depends solely by the experience of the researcher).
The Newton Descent algorithm can be summarized as follows:
Step #1: give an initial guess for the coordinates of the minimum point
x
0
(e.g. if the function under consideration has two unknowns x
1
and
x
2
, then x should be a two element row vector: x
0
=[
0
1
x ,
0
2
x ])
Step #2: perform an algorithm iteration, k, based on the following
formula:
11 +
= )]x(''f)[x('fxx
kkkk
for k=1,2,3,….
where )x(f
k
is the value of the function at k
th
iteration at point x,
)x('f
k
is a row vector that includes the first order partial derivatives of
f(.) w.r.t x’s at the k
th
iteration and
1
)]x(''f[
k
is a square matrix that
represents the inverse of the second order partial derivatives of f(.) w.r.t
x’s (Hessian matrix) at the k
th
iteration.
Vista de pagina 106
1 2 ... 102 103 104 105 106 107 108 109 110 111 112 ... 118 119

Comentarios a estos manuales

Sin comentarios