.. _method-multilevel_polynomial_chaos-orthogonal_least_interpolation:

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orthogonal_least_interpolation
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Build a polynomial chaos expansion from simulation samples using orthogonal least interpolation.


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

   method-multilevel_polynomial_chaos-orthogonal_least_interpolation-collocation_points_sequence
   method-multilevel_polynomial_chaos-orthogonal_least_interpolation-tensor_grid
   method-multilevel_polynomial_chaos-orthogonal_least_interpolation-reuse_points
   method-multilevel_polynomial_chaos-orthogonal_least_interpolation-import_build_points_file


**Specification**

- *Alias:* least_interpolation oli 

- *Arguments:* None


**Child Keywords:**

+-------------------------+--------------------+---------------------------------+---------------------------------------------+
| Required/Optional       | Description of     | Dakota Keyword                  | Dakota Keyword Description                  |
|                         | Group              |                                 |                                             |
+=========================+====================+=================================+=============================================+
| Required                                     | `collocation_points_sequence`__ | Sequence of collocation point counts used   |
|                                              |                                 | in a multi-stage expansion                  |
+----------------------------------------------+---------------------------------+---------------------------------------------+
| Optional                                     | `tensor_grid`__                 | Use sub-sampled tensor-product quadrature   |
|                                              |                                 | points to build a polynomial chaos          |
|                                              |                                 | expansion.                                  |
+----------------------------------------------+---------------------------------+---------------------------------------------+
| Optional                                     | `reuse_points`__                | This describes the behavior of reuse of     |
|                                              |                                 | points in constructing polynomial chaos     |
|                                              |                                 | expansion models.                           |
+----------------------------------------------+---------------------------------+---------------------------------------------+
| Optional                                     | `import_build_points_file`__    | File containing points you wish to use to   |
|                                              |                                 | build a surrogate                           |
+----------------------------------------------+---------------------------------+---------------------------------------------+

.. __: method-multilevel_polynomial_chaos-orthogonal_least_interpolation-collocation_points_sequence.html
__ method-multilevel_polynomial_chaos-orthogonal_least_interpolation-tensor_grid.html
__ method-multilevel_polynomial_chaos-orthogonal_least_interpolation-reuse_points.html
__ method-multilevel_polynomial_chaos-orthogonal_least_interpolation-import_build_points_file.html



**Description**


Build a polynomial chaos expansion from simulation samples using orthogonal least interpolation. Unlike the other regression methods ``expansion_order`` cannot be set. OLI will produce the lowest degree polynomial that interpolates the data