Gwcs

-------------------
Bug Fixes
^^^^^^^^^

- `world_axis_object_components` and `world_axis_object_classes` now ensure
unique keys in `CompositeFrame` and `CoordinateFrame`. [356]

- Fix issue where RuntimeWarning is raised when there are NaNs in coordinates
in angle wrapping code [367]

- Fix deprecation warning when wcs is initialized with a pipeline [368]

- Use ``CD`` formalism in ``WCS.to_fits_sip()``. [380]


New Features
^^^^^^^^^^^^
- ``wcs_from_points`` now includes fitting for the inverse transform. [349]

- Generalized ``WCS.to_fits_sip`` to be able to create a 2D celestial FITS WCS
from celestial subspace of the ``WCS``. Also, now `WCS.to_fits_sip``
supports arbitrary order of output axes. [357]


API Changes
^^^^^^^^^^^
- Modified interface to ``wcs_from_points`` function to better match analogous function
in astropy. [349]

- ``Model._BoundingBox`` was renamed to ``Model.ModelBoundingBox``. [376, 377]

-------------------
Bug Fixes
^^^^^^^^^
- Fix a regression with ``pixel_to_world`` for output frames with one axis. [342]

-------------------
New Features
^^^^^^^^^^^^

- Added an option to `to_fits_sip()` to be able to specify the reference
point (``crpix``) of the FITS WCS. [337]

- Added support for providing custom range of degrees in ``to_fits_sip``. [339]

Bug Fixes
^^^^^^^^^

- ``bounding_box`` now works with tuple of ``Quantities``. [331]

- Fix a formula for estimating ``crpix`` in ``to_fits_sip()`` so that ``crpix``
is near the center of the bounding box. [337]

- Allow sub-pixel sampling of the WCS model when computing SIP approximation in
``to_fits_sip()``. [338]

- Fixed a bug in ``to_fits_sip`` due to which ``inv_degree`` was ignored. [339]

-------------------
New Features
^^^^^^^^^^^^

- Added ``insert_frame`` method to modify the pipeline of a ``WCS`` object. [299]

- Added ``to_fits_tab`` method to generate FITS header and binary table
extension following FITS WCS ``-TAB`` convention. [295]

- Added ``in_image`` function for testing whether a point in world coordinates
maps back to the domain of definition of the forward transformation. [322]

- Implemented iterative inverse for some imaging WCS. [324]

-------------------
New Features
^^^^^^^^^^^^

- Updated versions of schemas for gwcs objects based on latest versions of
transform schemas in asdf-standard. [307]

- Added a ``wcs.Step`` class to allow serialization to ASDF to use references. [317]

- ``wcs.pipeline`` now is a list of ``Step`` instances instead of
a (frame, transform) tuple. Use ``WCS.pipeline.transform`` and
``WCS.pipeline.frame`` to access them. [319]

Bug Fixes
^^^^^^^^^

- Fix a bug in polygon fill for zero-width bounding boxes. [293]

- Add an optional parameter ``input_frame`` to ``wcstools.wcs_from_fiducial`. [312]

-------------------
New Features
^^^^^^^^^^^^

- Added two new transforms - ``SphericalToCartesian`` and
``CartesianToSpherical``. [275, 284, 285]

- Added ``to_fits_sip`` method to generate FITS header with SIP keywords [286]

- Added ``get_ctype_from_ucd`` function. [288]

Bug Fixes
^^^^^^^^^

- Fixed an off by one issue in ``utils.make_fitswcs_transform``. [290]