OOF2: The Manual
Name
OOF.Settings.Mesh_Defaults.Numerical_Differentiation — Set the increment used for approximate derivatives when exact derivatives are not available.
Synopsis
OOF.Settings.Mesh_Defaults.Numerical_Differentiation(epsilon
)
Details
- Parent Menu: OOF.Settings.Mesh_Defaults
-
Callback: function
_numericalDiff
in moduleooflib.engine.IO.meshmenu
-
Parameters:
epsilon
- Increment for numerical differentiation Type: A real number.
Description
When solving nonlinear equations with Newton's method, OOF2 needs to know
the derivatives of some of the material Properties
with respect to
the Field
values. If the Properties
don't provide code that
evaluates the derivatives, OOF2 can still use Newton's method by evaluating the
derivatives numerically. epsilon
sets the size
of the perturbation, relative to the Field
value, that is applied
to the Field
values when differentiating the Property
.
The default value of the relative perturbation is 10-5. An absolute perturbation less than 16 times the double precision machine epsilon will never be used.