mixed_hessians
Hessians are needed and will be obtained from a mix of numerical, analytic, and “quasi” sources
Specification
Alias: None
Arguments: None
Child Keywords:
Required/Optional 
Description of Group 
Dakota Keyword 
Dakota Keyword Description 

Optional 
Identify which numericalHessian corresponds to which response 

Optional (Choose One) 
Step Scaling 
(Default) Scale step size by the parameter value 

Do not scale stepsize 

Scale stepsize by the domain of the parameter 

Optional (Choose One) 
Finite Difference Type 
(Default) Use forward differences 

Use central differences 

Optional 
Identify which quasiHessian corresponds to which response 

Optional 
Identify which analytical Hessian corresponds to which response 
Description
The mixed_hessians
specification means that some Hessian
information is available directly from the simulation (analytic)
whereas the rest will have to be estimated by finite differences
(numerical) or approximated by secant updating. As for
mixed gradients, this specification allows the user to make use of as
much analytic information as is available and then
estimate/approximate the rest.
The id_analytic_hessians
list
specifies by number the functions which have analytic Hessians, and
the id_numerical_hessians
and id_quasi_hessians
lists specify by
number the functions which must use numerical Hessians and
secant Hessian updates, respectively. Each function identifier,
from 1 through the total number of functions, must appear once and
only once within the union of the id_analytic_hessians
,
id_numerical_hessians
, and id_quasi_hessians
lists.
The
fd_hessian_step_size
and bfgs
, damped
bfgs
, or sr1
secant update selections are as described previously in
responses
and pertain to those functions
listed by the id_numerical_hessians
and id_quasi_hessians
lists.