.. _method-moga-mutation_type:

"""""""""""""
mutation_type
"""""""""""""


Select a mutation type for JEGA methods


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

   method-moga-mutation_type-bit_random
   method-moga-mutation_type-replace_uniform
   method-moga-mutation_type-offset_normal
   method-moga-mutation_type-offset_cauchy
   method-moga-mutation_type-offset_uniform
   method-moga-mutation_type-mutation_rate


**Specification**

- *Alias:* None

- *Arguments:* None

- *Default:* replace_uniform


**Child Keywords:**

+-------------------------+--------------------+---------------------+-----------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword      | Dakota Keyword Description                    |
|                         | Group              |                     |                                               |
+=========================+====================+=====================+===============================================+
| Required (Choose One)   | Mutation Type      | `bit_random`__      | Mutate by flipping a random bit               |
|                         |                    +---------------------+-----------------------------------------------+
|                         |                    | `replace_uniform`__ | Use uniformly distributed value over range of |
|                         |                    |                     | parameter                                     |
|                         |                    +---------------------+-----------------------------------------------+
|                         |                    | `offset_normal`__   | Set mutation offset to use a normal           |
|                         |                    |                     | distribution                                  |
|                         |                    +---------------------+-----------------------------------------------+
|                         |                    | `offset_cauchy`__   | Use a Cauchy distribution for the mutation    |
|                         |                    |                     | offset                                        |
|                         |                    +---------------------+-----------------------------------------------+
|                         |                    | `offset_uniform`__  | Set mutation offset to use a uniform          |
|                         |                    |                     | distribution                                  |
+-------------------------+--------------------+---------------------+-----------------------------------------------+
| Optional                                     | `mutation_rate`__   | Set probability of a mutation                 |
+----------------------------------------------+---------------------+-----------------------------------------------+

.. __: method-moga-mutation_type-bit_random.html
__ method-moga-mutation_type-replace_uniform.html
__ method-moga-mutation_type-offset_normal.html
__ method-moga-mutation_type-offset_cauchy.html
__ method-moga-mutation_type-offset_uniform.html
__ method-moga-mutation_type-mutation_rate.html



**Description**


Five mutation types are available for selection by keyword:
``replace_uniform``, ``bit_random``, ``offset_cauchy``, ``offset_normal``, and
``offset_uniform``. They are described in greater detail on their
respective keyword pages.

The ``offset_*`` mutators all act by adding a random "offset" to a variable
value. The random amount has a mean of zero in all cases. The size of the offset
is controlled using the ``mutation_scale`` keyword, which is interpreted
differently for each ``offset_*`` type.

The rate of mutations for all types is controlled suing the ``mutation_rate``.
The rate is applied differently in each ``mutation_type``.


