.. _model-random_field-expansion_form:

""""""""""""""
expansion_form
""""""""""""""


Specify the form of the expansion to be used in the random field representation.
THIS IS AN EXPERIMENTAL CAPABILITY.


.. toctree::
   :hidden:
   :maxdepth: 1

   model-random_field-expansion_form-karhunen_loeve
   model-random_field-expansion_form-principal_components


**Specification**

- *Alias:* None

- *Arguments:* None


**Child Keywords:**

+-------------------------+--------------------+--------------------------+---------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword           | Dakota Keyword Description                  |
|                         | Group              |                          |                                             |
+=========================+====================+==========================+=============================================+
| Required (Choose One)   | Reduced Basis Type | `karhunen_loeve`__       | Specify Karhunen-Loeve as the expansion     |
|                         |                    |                          | form to be used in the random field         |
|                         |                    |                          | representation. THIS IS AN EXPERIMENTAL     |
|                         |                    |                          | CAPABILITY.                                 |
|                         |                    +--------------------------+---------------------------------------------+
|                         |                    | `principal_components`__ | Specify Principal Components as the form of |
|                         |                    |                          | the expansion to be used in the random      |
|                         |                    |                          | field representation. THIS IS AN            |
|                         |                    |                          | EXPERIMENTAL CAPABILITY.                    |
+-------------------------+--------------------+--------------------------+---------------------------------------------+

.. __: model-random_field-expansion_form-karhunen_loeve.html
__ model-random_field-expansion_form-principal_components.html



**Description**


This control allows the user to specify the form of
the random field representation (e.g. either a Karhunen-Loeve or Principal Components expansion).
THIS IS AN EXPERIMENTAL CAPABILITY UNDER ACTIVE DEVELOPMENT.

*Default Behavior*
The default expansion form is Karhunen-Loeve.