.. _filters.returns:

filters.returns
===============================================================================

The **Returns Filter** takes a single PointView as its input and creates a
``PointView`` for each of the user-specified groups_ defined below.

"first" is defined as those points whose ``ReturnNumber`` is 1 when the ``NumberOfReturns`` is greater than 1.

"intermediate" is defined as those points whose ``ReturnNumber`` is greater than 1 and less than ``NumberOfReturns`` when ``NumberOfReturns`` is greater than 2.

"last" is defined as those points whose ``ReturnNumber`` is equal to ``NumberOfReturns`` when ``NumberOfReturns`` is greater than 1.

"only" is defined as those points whose ``NumberOfReturns`` is 1.

.. embed::

Example
-------

This example creates two separate output files for the "last" and "only"
returns.

.. code-block:: json

  [
      "input.las",
      {
          "type":"filters.returns",
          "groups":"last,only"
      },
      "output_#.las"
  ]

Options
-------

_`groups`
  Comma-separated list of return number groupings. Valid options are "first",
  "last", "intermediate" or "only". [Default: "last"]
