.. _method-nonlinear_cg:

""""""""""""
nonlinear_cg
""""""""""""


(Experimental) nonlinear conjugate gradient optimization



**Topics**


local_optimization_methods


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

   method-nonlinear_cg-misc_options
   method-nonlinear_cg-convergence_tolerance
   method-nonlinear_cg-max_iterations
   method-nonlinear_cg-scaling
   method-nonlinear_cg-model_pointer


**Specification**

- *Alias:* None

- *Arguments:* None


**Child Keywords:**

+-------------------------+--------------------+---------------------------+---------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword            | Dakota Keyword Description                  |
|                         | Group              |                           |                                             |
+=========================+====================+===========================+=============================================+
| Optional                                     | `misc_options`__          | Options for nonlinear CG optimizer          |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `convergence_tolerance`__ | Stopping criterion based on objective       |
|                                              |                           | function or statistics convergence          |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `max_iterations`__        | Number of iterations allowed for optimizers |
|                                              |                           | and adaptive UQ methods                     |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `scaling`__               | Turn on scaling for variables, responses,   |
|                                              |                           | and constraints                             |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `model_pointer`__         | Identifier for model block to be used by a  |
|                                              |                           | method                                      |
+----------------------------------------------+---------------------------+---------------------------------------------+

.. __: method-nonlinear_cg-misc_options.html
__ method-nonlinear_cg-convergence_tolerance.html
__ method-nonlinear_cg-max_iterations.html
__ method-nonlinear_cg-scaling.html
__ method-nonlinear_cg-model_pointer.html



**Description**


This method is an incomplete experimental implementation of nonlinear
conjugate gradient optimization, a local, gradient-based solver.