.. _method-sampling-sample_type-low_discrepancy-digital_net-generating_matrices-predefined:

""""""""""
predefined
""""""""""


Specify predefined generating matrices



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

   method-sampling-sample_type-low_discrepancy-digital_net-generating_matrices-predefined-joe_kuo
   method-sampling-sample_type-low_discrepancy-digital_net-generating_matrices-predefined-sobol_order_2


**Specification**

- *Alias:* None

- *Arguments:* None

- *Default:* Default generating matrices


**Child Keywords:**

+-------------------------+--------------------+--------------------+-----------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword     | Dakota Keyword Description                    |
|                         | Group              |                    |                                               |
+=========================+====================+====================+===============================================+
| Required (Choose One)   | Predefined         | `joe_kuo`__        | Generating matrices that provide up to 2\     |
|                         | Generating         |                    | :sup:`32` points in up to 250 dimensions      |
|                         | Matrices           +--------------------+-----------------------------------------------+
|                         |                    | `sobol_order_2`__  | Generating matrices that provide up to 2\     |
|                         |                    |                    | :sup:`32` points in up to 1024 dimensions     |
+-------------------------+--------------------+--------------------+-----------------------------------------------+

.. __: method-sampling-sample_type-low_discrepancy-digital_net-generating_matrices-predefined-joe_kuo.html
__ method-sampling-sample_type-low_discrepancy-digital_net-generating_matrices-predefined-sobol_order_2.html



**Description**


Dakota provides two predefined generating vectors:

- :dakkw:`method-sampling-sample_type-low_discrepancy-digital_net-generating_matrices-predefined-joe_kuo` (default): generates up to 2\ :sup:`32` points in up to 250 dimensions :cite:p:`Joe08`
- :dakkw:`method-sampling-sample_type-low_discrepancy-digital_net-generating_matrices-predefined-sobol_order_2`: generates up to 2\ :sup:`32` points in up to 1024 dimensions :cite:p:`QMCPy`




**Examples**



.. code-block::

    environment
      tabular_data
        tabular_data_file = 'samples.dat'
        freeform

    method
      sampling
        samples 1024
        sample_type
          low_discrepancy
            digital_net
              generating_matrices predefined joe_kuo

    variables
      uniform_uncertain = 2
        lower_bounds 0.0 0.0
        upper_bounds 1.0 1.0

    interface
      analysis_drivers = 'genz'
      analysis_components = 'cp1'
      direct

    responses
      response_functions = 1
      no_gradients
      no_hessians



