pi
==============================================

Purpose
----------------
Returns the mathematical constant :math:`π`.

Format
----------------
.. function:: y = pi

    :return y: the value of :math:`\pi`.
    :rtype y: scalar

Examples
----------------

::

    // Print 14 digits and allow 16 digits worth of space for
    // each printed number
    format /rdn 16,14;
    print pi;

will return:

::

    3.14159265358979