Introduction
------------

pywcs is a set of routines for handling the FITS World Coordinate
System (WCS) standard.  It is a thin wrapper around the high- and
mid-level interfaces of Dr. Mark Calabretta's WCSLIB available here:

  http://www.atnf.csiro.au/people/mcalabre/WCS/

In addition, there are extensions (written in C) to support Spitzer
Simple Imaging Polynomial (SIP) convention keywords and Paper IV table
lookup distortion.

Please direct any questions to:

  help@stsci.edu

Build instructions
------------------

pywcs includes its own copy of WCSLIB.

pywcs requires:

  - Numpy 1.3 or later
  - pyfits 1.4 or later

pywcs uses the standard Python distutils system to build and install
itself.  From the command line run::

    python setup.py install

to install pywcs.

Building documentation
----------------------

Optionally, the documentation can be built using Sphinx
(http://sphinx.pocoo.org).

After installing pywcs, 'cd' into the 'doc' directory and::

    make html

The documentation is also available online at:

    http://stsdas.stsci.edu/astrolib/pywcs/index.html