.. _method-sampling-sample_type-low_discrepancy-rank_1_lattice-ordering-radical_inverse:

"""""""""""""""
radical_inverse
"""""""""""""""


Radical inverse ordering of the points of this rank-1 lattice



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



**Specification**

- *Alias:* None

- *Arguments:* None


**Description**


Returns the points in radical inverse order. This is the default setting.

*Usage tips*

The advantage of the radical inverse ordering is that one can 
generate a good point set with an arbitrary number of points :math:`N`.




**Examples**



.. code-block::

    environment
      tabular_data
        tabular_data_file = 'samples.dat'
        freeform

    method
      sampling
        samples 8
        sample_type
          low_discrepancy
            rank_1_lattice
              generating_vector inline 1 5 # this is a Fibonacci lattice
              m_max 3 # 8 points in total
              no_random_shift
              ordering radical_inverse

    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



