.. _model-surrogate-global-gaussian_process-export_approx_variance_file:

"""""""""""""""""""""""""""
export_approx_variance_file
"""""""""""""""""""""""""""


Output file for surrogate model variance evaluations


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

   model-surrogate-global-gaussian_process-export_approx_variance_file-custom_annotated
   model-surrogate-global-gaussian_process-export_approx_variance_file-annotated
   model-surrogate-global-gaussian_process-export_approx_variance_file-freeform


**Specification**

- *Alias:* None

- *Arguments:* STRING

- *Default:* no variance export to a file


**Child Keywords:**

+-------------------------+--------------------+----------------------+-----------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword       | Dakota Keyword Description                    |
|                         | Group              |                      |                                               |
+=========================+====================+======================+===============================================+
| Optional (Choose One)   | Tabular Format     | `custom_annotated`__ | Selects custom-annotated tabular file format  |
|                         |                    +----------------------+-----------------------------------------------+
|                         |                    | `annotated`__        | Selects annotated tabular file format         |
|                         |                    +----------------------+-----------------------------------------------+
|                         |                    | `freeform`__         | Selects freeform file format                  |
+-------------------------+--------------------+----------------------+-----------------------------------------------+

.. __: model-surrogate-global-gaussian_process-export_approx_variance_file-custom_annotated.html
__ model-surrogate-global-gaussian_process-export_approx_variance_file-annotated.html
__ model-surrogate-global-gaussian_process-export_approx_variance_file-freeform.html



**Description**


Specifies a file in which the points (input variable values) at which
the surrogate model is evaluated and corresponding response
*variance* values computed by the surrogate model will be
written.  The response values are the surrogate's predicted
approximation to the truth model responses at those points.

*Usage Tips*

Dakota exports tabular data in one of three formats:

- ``annotated`` (default)
- ``custom_annotated``
- ``freeform``