.. _`Match Table lengths`:

.. _`org.sysess.sympathy.data.table.matchtwotables`:

Match Table lengths
```````````````````

.. image:: match_tables.svg
   :width: 48


Ensure that two Tables match (i.e. have the same number of rows) by adding or removing rows in one of them.




Documentation
:::::::::::::

To compare the number of rows in two :ref:`Tables` and resize one of them,
in order to have two Tables with equal numbers of rows, is the
functionality of the nodes in the considered category. For example, this
may be helpful if one would like to horisontal join two Tables with
different number of rows, which is not possible according to the definition
of a Table, see :ref:`Tables` and :ref:`HJoin Table`.

In the procedure of the node, the Table connected to the upper of the two
inputs is used as reference while the Table coming in through the lower
port is the one that is going to be modified. The modification can either
be a contraction or an extension of the Table depending if it is longer or
shorter than the reference Table, respectively.

The extension will be preformed according to one of the following
strategies:

    - Use last value
    - Fill with zeroes (or empty strings/dates or similar)
    - Fill with NaNs (or None or similar)


Definition
::::::::::


Input ports
...........

    **guide**  table
        Guide

    **input**  table
        Input Table


Output ports
............

    **output**  table
        Length matched Table




Configuration
.............

    **Extend values** (fill)
        Specify the values to use if the input has to be extended.







Examples
........

* :download:`MatchTableLengths.syx </Examples/Sympathy/Data Processing/Structure/MatchTableLengths.syx>`




Implementation
..............

.. automodule:: node_match_tables
    :noindex:

.. class:: MatchTwoTables
    :noindex: