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# Source code for astropy.wcs

    # Licensed under a 3-clause BSD style license - see LICENSE.rst
    """
    .. _wcslib: http://www.atnf.csiro.au/~mcalabre/WCS/
    .. _FITS WCS standard: http://fits.gsfc.nasa.gov/fits_wcs.html
    .. _distortion paper: http://www.atnf.csiro.au/people/mcalabre/WCS/dcs_20040422.pdf
    .. _SIP: http://irsa.ipac.caltech.edu/data/SPITZER/docs/files/spitzer/shupeADASS.pdf

    `astropy.wcs` contains utilities for managing World Coordinate System
    (WCS) transformations in FITS files.  These transformations map the
    pixel locations in an image to their real-world units, such as their
    position on the sky sphere.

    It performs three separate classes of WCS transformations:

    - Core WCS, as defined in the `FITS WCS standard`_, based on Mark
      Calabretta's `wcslib`_.  See `~astropy.wcs.Wcsprm`.
    - Simple Imaging Polynomial (`SIP`_) convention.  See
      `~astropy.wcs.Sip`.
    - table lookup distortions as defined in WCS `distortion paper`_.  See
      `~astropy.wcs.DistortionLookupTable`.

    Each of these transformations can be used independently or together in
    a standard pipeline.
    """

    from __future__ import division  # confidence high

    try:
        # Not guaranteed available at setup time
        from .wcs import *
        from . import utils
    except ImportError:
        if not _ASTROPY_SETUP_:
            raise

    def get_include():
        """
        Get the path to astropy.wcs's C header files.
        """
        import os
        return os.path.join(os.path.dirname(__file__), "include")