.. _eck4:

********************************************************************************
Eckert IV
********************************************************************************

.. image:: ./images/eck4.png
   :scale: 50%
   :alt:   Eckert IV


.. math::

    x = \lambda(1+cos\phi) / \sqrt{ 2 + \pi }

.. math::
    y = 2 \phi / \sqrt { 2 + \pi }

Parameters
################################################################################

.. note:: All parameters are optional for the Eckert IV projection.

.. include:: ../options/lon_0.rst

.. include:: ../options/R.rst

.. include:: ../options/x_0.rst

.. include:: ../options/y_0.rst