NOX Thyra Group Options

The optional Thyra Group Options sublist controls residual and Jacobian scaling in the Thyra-backed NOX group.

<Thyra Group Options>

The Thyra nonlinear-solver adapter parses this top-level NOX sublist when it constructs the NOX group. It is not specific to the pseudo-transient solver. No searched Vertex-CFD input populates it.

Function Scaling
Type:

string

Value:

"None", "Row Sum", or "User Defined"

Usage:

Optional

Default:

"None"

Description:

Selects residual and Jacobian scaling. "Row Sum" creates a row-sum scaling vector. "User Defined" requires the C++ vector entry documented below and therefore cannot be configured using XML values alone.

Update Row Sum Scaling
Type:

string

Value:

"Before Each Nonlinear Solve" or "Before Each Nonlinear Iteration"

Usage:

Optional with Function Scaling = "Row Sum"

Default:

"Before Each Nonlinear Solve"

Description:

Selects when the inverse row-sum scaling vector is recomputed.

User Defined Scaling
Type:

Teuchos::RCP<Thyra::VectorBase<double>>

Value:

C++ vector object

Usage:

Required with Function Scaling = "User Defined"

Default:

Teuchos::null

Description:

Supplies the user-defined function-scaling vector. This object-valued entry cannot be constructed by the Vertex-CFD XML input.

Do Right Scaling First
Type:

bool

Value:

true or false

Usage:

Optional

Default:

false

Description:

Controls the ordering when both right scaling and function scaling are present. The right-scaling vectors are C++ object entries on the NOX list and are not configurable as ordinary Vertex-CFD XML values.

Example

Listing 18 Default Thyra group scaling options for an implicit solve.
1<ParameterList name="Thyra Group Options">
2  <Parameter name="Function Scaling" type="string" value="None"/>
3  <Parameter name="Update Row Sum Scaling" type="string" value="Before Each Nonlinear Solve"/>
4  <Parameter name="Do Right Scaling First" type="bool" value="false"/>
5</ParameterList>