==========================
New Features
------------
astropy.convolution
^^^^^^^^^^^^^^^^^^^
- Modified Cython functions to release the GIL. This enables convolution
to be parallelized effectively and gives large speedups when used with
multithreaded task schedulers such as Dask. [3949]
API Changes
-----------
astropy.coordinates
^^^^^^^^^^^^^^^^^^^
- Some transformations for an input coordinate that's a scalar now correctly
return a scalar. This was always the intended behavior, but it may break
code that has been written to work-around this bug, so it may be viewed as
an unplanned API change [3920, 4039]
astropy.visualization
^^^^^^^^^^^^^^^^^^^^^
- The ``astropy_mpl_style`` no longer sets ``interactive`` to ``True``, but
instead leaves it at the user preference. This makes using the style
compatible with building docs with Sphinx, and other non-interactive
contexts. [4030]
Bug Fixes
---------
astropy.coordinates
^^^^^^^^^^^^^^^^^^^
- Fix bug where coordinate representation setting gets reset to default value
when coordinate array is indexed or sliced. [3824]
- Fixed confusing warning message shown when using dates outside current IERS
data. [3844]
- ``get_sun`` now yields a scalar when the input time is a scalar (this was a
regression in v1.0.3 from v1.0.2) [3998, 4039]
- Fixed bug where some scalar coordinates were incorrectly being changed to
length-1 array coordinates after transforming through certain frames.
[3920, 4039]
- Fixed bug causing the ``separation`` methods of ``SkyCoord`` and frame
classes to fail due to infinite recursion [4033, 4039]
- Made it so that passing in a list of ``SkyCoord`` objects that are in
UnitSphericalRepresentation to the ``SkyCoord`` constructor appropriately
yields a new object in UnitSphericalRepresentation [3938, 4039]
astropy.cosmology
^^^^^^^^^^^^^^^^^
- Fixed wCDM to not ignore the Ob0 parameter on initialization. [3934]
astropy.io.fits
^^^^^^^^^^^^^^^
- Fixed crash when updating data in a random groups HDU opened in update
mode. [3730]
- Fixed incorrect checksum / datasum being written when re-writing a scaled
HDU (i.e. non-trivial BSCALE and/or BZERO) with
``do_not_scale_image_data=False``. [3883]
- Fixed stray deprecation warning in ``BinTableHDU.copy()``. [3798]
- Better handling of the ``BLANK`` keyword when auto-scaling scaled image
data. The ``BLANK`` keyword is now removed from the header after
auto-scaling is applied, and it is restored properly (with floating point
NaNs replaced by the filler value) when updating a file opened with the
``scale_back=True`` argument. Invalid usage of the ``BLANK`` keyword is
also better warned about during validation. [3865]
- Reading memmaped scaled images won't fail when
``do_not_scale_image_data=True`` (that is, since we're just reading the raw
/ physical data there is no reason mmap can't be used). [3766]
- Fixed a reference cycle that could sometimes cause FITS table-related
objects (``BinTableHDU``, ``ColDefs``, etc.) to hang around in memory
longer than expected. [4012]
astropy.modeling
^^^^^^^^^^^^^^^^
- Improved support for pickling of compound models, including both compound
model instances, and new compound model classes. [3867]
- Added missing default values for ``Ellipse2D`` parameters. [3903]
astropy.time
^^^^^^^^^^^^
- Fixed iteration of scalar ``Time`` objects so that ``iter()`` correctly
raises a ``TypeError`` on them (while still allowing ``Time`` arrays to be
iterated). [4048]
astropy.units
^^^^^^^^^^^^^
- Added frequency-equivalency check when declaring doppler equivalencies
[3728]
- Define ``floor_divide`` (``//``) for ``Quantity`` to be consistent
``divmod``, such that it only works where the quotient is dimensionless.
This guarantees that ``(q1 // q2) * q2 + (q1 % q2) == q1``. [3817]
- Fixed the documentation of supported units to correctly report support for
SI prefixes. Previously the table of supported units incorrectly showed
several derived unit as not supporting prefixes, when in fact they do.
[3835]
- Fix a crash when calling ``astropy.units.cds.enable()``. This will now
"set" rather than "add" units to the active set to avoid the namespace
clash with the default units. [3873]
- Ensure in-place operations on ``float32`` quantities work. [4007]
astropy.utils
^^^^^^^^^^^^^
- The ``deprecated`` decorator did not correctly wrap classes that have a
custom metaclass--the metaclass could be dropped from the deprecated
version of the class. [3997]
- The ``wraps`` decorator would copy the wrapped function's name to the
wrapper function even when ``'__name__'`` is excluded from the ``assigned``
argument. [4016]
Misc
^^^^
- ``fitscheck`` no longer causes scaled image data to be rescaled when
adding checksums to existing files. [3884]
- Fixed an issue where running ``import astropy`` from within the source
tree did not automatically build the extension modules if the source is
from a source distribution (as opposed to a git repository). [3932]
- Fixed multiple instances of a bug that prevented Astropy from being used
when compiled with the ``python -OO`` flag, due to it causing all
docstrings to be stripped out. [3923]
- Removed source code template files that were being installed
accidentally alongside installed Python modules. [4014]
- Fixed a bug in the exception logging that caused a crash in the exception
handler itself on Python 3 when exceptions do not include a message.
[4056]