.. _install:

************
Installation
************

This chapter reviews a couple of different ways of installing PyKYLIE
on your system.

Pre-requisites
==============

PyKYLIE requires that the following Python packages are already present:

* `NumPy <https://numpy.org/>`__
* `SciPy <https://scipy.org/>`__
* `Astropy <https://www.astropy.org/>`__
* `PyMSG <https://msg.readthedocs.io/>`__

If you opt to install from PyPI (below), then these pre-requisites
should be taken care of automatically, with the exception of PyMSG
(which must be installed manually *before* you try to install PyKYLIE).

Installing from PyPI
====================

To install PyKYLIE from the `Python Package Index (PyPI)
<https://pypi.org/>`__, use the :command:`pip` command:

.. code-block:: console

   $ pip install pykylie

If PyKYLIE is already installed, you can upgrade to a more-recent
version via

.. code-block:: console

   $ pip install --upgrade pykylie

Installing from Source
======================

To install PyKYLIE from source, download the `source code
<tarball_url_>`__ and unpack it from the command line using the
:command:`tar` utility:

.. code-block:: console
   :substitutions:

   $ tar xf |tarball|

Then, use :command:`pip` to install it:

.. code-block:: console
   :substitutions:

   $ pip install ./|dist_dir|