Ligo.skymap

==================

- Display at least three significant figures in the credible area shown in the
plots produced by the command line tool ``ligo-skymap-plot`` so that a
nonzero value is printed if the area is less than 1 deg2.

- Adjust boundary conditions for linear interpolation of credible areas so that
nonzero values are reported when the credible region is smaller than one
pixel.

==================

- Add sign convention for `gstlal_inspiral_coinc_extractor`, the program that
is used to upload offline GstLAL events to GraceDB.

==================

- Fix blank volume rendering plots for very well-localized events due to
`changes in data type promotion rules in Numpy 2.x`__.

__ https://numpy.org/devdocs/numpy_2_0_migration_guide.html#changes-to-numpy-data-type-promotion

- Restore support for Numpy 1.x while keeping support for Numpy 2.x.

==================

- BAYESTAR now terminates gracefully if you interrupt it by typing control-C or
sending the process in which it is running a SIGINT signal. Previously, there
was a bug in the signal handling code that caused it to segfault on keyboard
interrupt.

Note that if you invoke BAYESTAR multiple times in different threads of the
same process, then only one of the invocations will stop early due the
interrupt, because signal handlers are process-wide.

- Enhancements to the command-line tool ``ligo-skymap-plot``:

- Read in and reproject sky maps in multi-resolution format. This
significantly decreases memory consumption when plotting high-resolution
sky maps.

- The algorithm that calculates credible areas printed in the plot legend
now matches the algorithm in ``ligo.skymap.postprocess.crossmatch``: it
does linear interpolation of area when the credible level falls between
pixels.

- The ``ligo-skymap-plot-volume`` script now uses multi-resolution sky maps
internally. This will significantly decrease its memory usage for
high-resolution sky maps.

- Use a Wayback Machine URL to download the Mellinger sky panorama because the
original URL is broken.

- Fixes related to the ``cut_dateline`` and ``cut_prime_meridian`` functions:

- Adjust to API changes between Shapely 1.x and 2.x.

- Add a dependency on Shapely.

- Add test cases.

- Require numpy ≥ 2.0.0 due to changes in string representations of scalars
that affected doctest test cases. See `astropy/astropy15095`__.

__ https://github.com/astropy/astropy/issues/15095

- There are now nightly builds of ligo.skymap. For instructions on installing
the latest, unreleased, bleeding-edge version of ligo.skyamp, see
https://lscsoft.docs.ligo.org/ligo.skymap/develop.html#nightly-builds.

==================

- Drop support for Python 3.9 because Astropy 6.1.0 dropped Python 3.9 in
accordance with the Numpy version support policy.

- Require astropy >= 6.0.0.

- Fix a memory alignment bug that caused ``ligo.skymap.moc.rasterize``
and ``ligo-skymap-flatten`` to produce incorrect results for multiresolution
sky maps that have an odd number of 32-bit columns. This impacted Swift BAT
GUANO localizations which have a single 32-bit PROBDENSITY column.

- Ensure that ``ligo.skymap.distance.conditional_cdf`` and
``ligo.skymap.distance.marginal_cdf`` correctly handle corner cases for
extreme values: both now return 0 for distances that are less than or equal
to 0, and 1 for a distance of positive infinity (assuming that the
``distnorm`` argument does indeed normalize the distribution).

- Ensure that all ligo.skymap command-line tools close any files that they have
opened. These command-line tools are used as functions in GWCelery, and were
leaking unclosed file descriptors.

==================

- Added options to center ``mollweide`` and ``aitoff`` projections. Thanks go
to Sam Wyatt for this contribution.

- Added support for ``os.PathLike`` filenames when reading ligolw files. Thanks
go to Thomas Sainrat for this contribution.

- Check for more invalid input corner cases in ``ligo.skymap.moc.rasterize``.

- Remove the ``--min-inclination`` and ``max-inclination`` options from
``bayestar-localize-coincs`` and ``bayestar-localize-lvalert``. These options
are rarely used, and will be made obsolete by a future release that adds
inclination posteriors to sky map output.

- Remove ``frameon=False`` in ``ligo-skymap-plot-volume`` so that it respects
the (lack of the) ``--transparent`` option. This improves text and label
readability against dark backgrounds when transparent mode is not on. Thanks
go to Geoffrey Mo for this contribution.

- Add documentation on the LIGO Scientific Collaboration (LSC) review process
to the Testing section of the manual.

- Require Numpy >= 1.23.0. Rebuild for binary compatibility with Numpy 2.0.0.

- Add unit tests for Python 3.12.