.. _model-random_field-build_source-analytic_covariance:

"""""""""""""""""""
analytic_covariance
"""""""""""""""""""


Use an analytic covariance function for the purposes
of generating a random field model.
THIS IS AN EXPERIMENTAL CAPABILITY.


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

   model-random_field-build_source-analytic_covariance-squared_exponential
   model-random_field-build_source-analytic_covariance-exponential


**Specification**

- *Alias:* None

- *Arguments:* None


**Child Keywords:**

+-------------------------+--------------------+-------------------------+---------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword          | Dakota Keyword Description                  |
|                         | Group              |                         |                                             |
+=========================+====================+=========================+=============================================+
| Required (Choose One)   | Covariance Kernel  | `squared_exponential`__ | Specify a squared exponential covariance in |
|                         | Form               |                         | the case where the random field is built    |
|                         |                    |                         | from an analytic covariance functio. THIS   |
|                         |                    |                         | IS AN EXPERIMENTAL CAPABILITY.              |
|                         |                    +-------------------------+---------------------------------------------+
|                         |                    | `exponential`__         | Specify an exponential covariance in the    |
|                         |                    |                         | case where the random field is built from   |
|                         |                    |                         | an analytic covariance functio. THIS IS AN  |
|                         |                    |                         | EXPERIMENTAL CAPABILITY.                    |
+-------------------------+--------------------+-------------------------+---------------------------------------------+

.. __: model-random_field-build_source-analytic_covariance-squared_exponential.html
__ model-random_field-build_source-analytic_covariance-exponential.html



**Description**


As part of the capability to generate a random field representation, the user
needs to specify the data used to generate the random field representation.
If ``analytic_covariance`` is specified, an analytic covariance function will be used to generate instantiations
of a random field over a mesh.
The form of the covariance function must be specified (e.g. ``exponential`` or ``squared_exponential``.
THIS IS AN EXPERIMENTAL CAPABILITY UNDER ACTIVE DEVELOPMENT.

*Default Behavior*
Currently, the ``build_source`` that is fully working is the
``dace_method_pointer``.  The others are not fully operational.