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

"""""""
natural
"""""""


Natural ordering of the points of this rank-1 lattice



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



**Specification**

- *Alias:* None

- *Arguments:* None


**Description**


Returns the points in natural order.

*Usage Tips*

When the ``natural`` ordering of the points is used, it is implicitly assumed that the user will 
only request a number of points that is a power of 2. Failing to do so will result in a set of points 
for which one or more dimensions are not uniformly covered, resulting in bad low-discrepancy properties, 
and ultimately bad performance of the method that uses these points. It is recommended to not use this option unless you know what you're doing.




**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 natural # this is fine since we generate 2^3 = 8 samples

    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



