.. _method-nonlinear_cg:

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


(Experimental) nonlinear conjugate gradient optimization



**Topics**


local_optimization_methods


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

   method-nonlinear_cg-id_method
   method-nonlinear_cg-output
   method-nonlinear_cg-final_solutions
   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                                     | `id_method`__             | Name the method block; helpful when there are |
|                                              |                           | multiple                                      |
+----------------------------------------------+---------------------------+-----------------------------------------------+
| Optional                                     | `output`__                | Control how much method information is        |
|                                              |                           | written to the screen and output file         |
+----------------------------------------------+---------------------------+-----------------------------------------------+
| Optional                                     | `final_solutions`__       | Number of designs returned as the best        |
|                                              |                           | solutions                                     |
+----------------------------------------------+---------------------------+-----------------------------------------------+
| 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-id_method.html
__ method-nonlinear_cg-output.html
__ method-nonlinear_cg-final_solutions.html
__ 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.