Blurb::
Uses a file to import a user-specified MCMC proposal covariance.
Description::
This keyword selection results in definition of the MCMC
proposal covariance from importing data a user-specified filename.
This import must be declared as either a full matrix or a matrix diagonal.

*Default Behavior*

This option is not the default, and generally implies special a priori
knowledge from the user.

*Usage Tips*

This option is not supported for the case of transformations to
standardized probability space.
Topics::

Examples::

.. code-block::

    method,
            bayes_calibration queso
             samples = 1000 seed = 348
              dram
              proposal_covariance
                filename ... # See leaf nodes for required format option


Theory::

Faq::

See_Also::
