------------------
This is a major new release of **pyregion**. There are some API changes
(listed below), but overall our goal was to keep backwards-compatibility
as much as possible while fixing code and installation issues
and refactor the internals to use Astropy more.
We note that we are developing a new **regions** package that is supposed
to become a superset of the functionality that is now in **pyregion** and
might be moved in the Astropy core package as **astropy.regions** in the future.
The main difference is that it represents regions as classes and uses Astropy
angle and coordinate objects, allowing for easier region-based analysis.
It is not feature complete, especially the DS9 region file parser is not a
complete replacement for **pyregion** yet. Still, you are encouraged to try
it out ( http://astropy-regions.readthedocs.io/ ), give feedback or even contribute.
For **pyregion**, the plan is to continue to do bugfixes and releases,
but to keep API changes to a minimum to avoid breaking existing scripts or pipelines.
If you have any questions or issues or requests, please open an issue in the **pyregion**
issue tracker on Github.
API Changes
^^^^^^^^^^^
- Removed ``rot_wrt_axis`` parameter from ``ShapeList`` and internal methods.
- ``ShapeList.as_imagecoord`` no longer accepts a ``asropy.wcs.WCS`` object. The
conversion from pixel to image coordinates depends on the center of the
image defined in ``astropy.io.fits.Header`` in order to agree with DS9.
- ``pyregion.ds9_region_parser``
- ``RegionParser.sky_to_image`` now calls its first parameter ``shape_list``
instead of ``l``.
- ``pyregion.extern``
- ``kapteyn_celestial`` removed.
- ``pyregion.wcs_converter``
- ``convert_to_imagecoord`` changed signature with the switch to Astropy
and takes a ``Shape`` object.
- ``convert_physical_to_imagecoord`` changed signature to accept a ``Shape``
object.
- ``pyregion.wcs_helper``
- All public methods and constants removed. They are replaced by Astropy,
or replaced by private methods.
Other Changes and Additions
^^^^^^^^^^^^^^^^^^^^^^^^^^^
- Astropy is used for all sky to image coordinate conversions. Science results may
change, as `SIP <http://irsa.ipac.caltech.edu/data/SPITZER/docs/files/spitzer/shupeADASS.pdf>`_
and `distortion paper <http://www.atnf.csiro.au/people/mcalabre/WCS/dcs_20040422.pdf>`_
corrections are now used if present in the FITS file.
- Headers with more then 2 axes are now supported; only the celestial axes are
used.
- Rotation angles are measured from the Y-axis instead of the X-axis, in order
to agree with DS9 and potentially other astronomy software. This is a change
from previous behavior, but only affects images with non-orthogonal axes.
Previously, this behavior was controlled by the ``rot_wrt_axis`` parameter.
- Astropy 1.0 is now required.
- Shape conversion for multi-dimenstional HDU does not raise exceptions.
- Parser supports hex color in attributes