.. _method-dace:

""""
dace
""""


Design and Analysis of Computer Experiments



**Topics**


package_ddace, design_and_analysis_of_computer_experiments


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

   method-dace-grid
   method-dace-random
   method-dace-oas
   method-dace-lhs
   method-dace-oa_lhs
   method-dace-box_behnken
   method-dace-central_composite
   method-dace-samples
   method-dace-seed
   method-dace-fixed_seed
   method-dace-main_effects
   method-dace-quality_metrics
   method-dace-variance_based_decomp
   method-dace-symbols
   method-dace-model_pointer


**Specification**

- *Alias:* None

- *Arguments:* None


**Child Keywords:**

+-------------------------+--------------------+---------------------------+---------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword            | Dakota Keyword Description                  |
|                         | Group              |                           |                                             |
+=========================+====================+===========================+=============================================+
| Required (Choose One)   | DACE type          | `grid`__                  | Grid Sampling                               |
|                         |                    +---------------------------+---------------------------------------------+
|                         |                    | `random`__                | Uses purely random Monte Carlo sampling to  |
|                         |                    |                           | sample variables                            |
|                         |                    +---------------------------+---------------------------------------------+
|                         |                    | `oas`__                   | Orthogonal Array Sampling                   |
|                         |                    +---------------------------+---------------------------------------------+
|                         |                    | `lhs`__                   | Uses Latin Hypercube Sampling (LHS) to      |
|                         |                    |                           | sample variables                            |
|                         |                    +---------------------------+---------------------------------------------+
|                         |                    | `oa_lhs`__                | Orthogonal Array Latin Hypercube Sampling   |
|                         |                    +---------------------------+---------------------------------------------+
|                         |                    | `box_behnken`__           | Box-Behnken Design                          |
|                         |                    +---------------------------+---------------------------------------------+
|                         |                    | `central_composite`__     | Central Composite Design                    |
+-------------------------+--------------------+---------------------------+---------------------------------------------+
| Optional                                     | `samples`__               | Number of samples for sampling-based        |
|                                              |                           | methods                                     |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `seed`__                  | Seed of the random number generator         |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `fixed_seed`__            | Reuses the same seed value for multiple     |
|                                              |                           | random sampling sets                        |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `main_effects`__          | ANOVA                                       |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `quality_metrics`__       | Calculate metrics to assess the quality of  |
|                                              |                           | quasi-Monte Carlo samples                   |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `variance_based_decomp`__ | Activates global sensitivity analysis based |
|                                              |                           | on decomposition of response variance into  |
|                                              |                           | contributions from variables                |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `symbols`__               | Number of replications in the sample set    |
+----------------------------------------------+---------------------------+---------------------------------------------+
| Optional                                     | `model_pointer`__         | Identifier for model block to be used by a  |
|                                              |                           | method                                      |
+----------------------------------------------+---------------------------+---------------------------------------------+

.. __: method-dace-grid.html
__ method-dace-random.html
__ method-dace-oas.html
__ method-dace-lhs.html
__ method-dace-oa_lhs.html
__ method-dace-box_behnken.html
__ method-dace-central_composite.html
__ method-dace-samples.html
__ method-dace-seed.html
__ method-dace-fixed_seed.html
__ method-dace-main_effects.html
__ method-dace-quality_metrics.html
__ method-dace-variance_based_decomp.html
__ method-dace-symbols.html
__ method-dace-model_pointer.html



**Description**


The Distributed Design and Analysis of Computer Experiments (DDACE)
library provides the following DACE techniques:

#. grid sampling ( ``grid``)
#. pure random sampling ( ``random``)
#. orthogonal array sampling ( ``oas``)
#. latin hypercube sampling ( ``lhs``)
#. orthogonal array latin hypercube sampling ( ``oa_lhs``)
#. Box-Behnken ( ``box_behnken``)
#. central composite design ( ``central_composite``)

These methods all generate point sets that may be used to drive a set of
computer experiments.  Note that all of the DACE methods generated
randomized designs, except for Box-Behnken and Central composite which
are classical designs.  That is, the grid sampling will generate a
randomized grid, not what one typically thinks of as a grid
of uniformly spaced points over a rectangular grid.  Similar,
the orthogonal array is a randomized version of an orthogonal
array:  it does not generate discrete, fixed levels.

In addition to the selection of the method, there are keywords
that affect the method outputs:

#. :dakkw:`method-dace-main_effects`
#. :dakkw:`method-dace-quality_metrics`
#. :dakkw:`method-dace-variance_based_decomp`

And keywords that affect the sampling:

#. :dakkw:`method-dace-fixed_seed`
#. :dakkw:`method-dace-symbols`
#. :dakkw:`method-dace-samples`
#. :dakkw:`method-dace-seed`