.. _method-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-polynomial_chaos-orthogonal_least_interpolation-collocation_points
   method-polynomial_chaos-orthogonal_least_interpolation-tensor_grid
   method-polynomial_chaos-orthogonal_least_interpolation-reuse_points
   method-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`__       | Number of collocation points used to        |
|                                              |                              | estimate expansion coefficients             |
+----------------------------------------------+------------------------------+---------------------------------------------+
| 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-polynomial_chaos-orthogonal_least_interpolation-collocation_points.html
__ method-polynomial_chaos-orthogonal_least_interpolation-tensor_grid.html
__ method-polynomial_chaos-orthogonal_least_interpolation-reuse_points.html
__ method-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