Sncosmo

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

- ``SFD98Map`` and ``get_ebv_from_map`` deprecated in favor of separate package
`sfdmap <http://github.com/kbarbary/sfdmap>`_ which has vastly improved
performance (200x faster) for the typical case of scalar coordinates in
ICRS frame.

- ``animate_source()`` deprecated. This is a "fun extra" that is difficult
to test and no longer seems to work.

- Cython implementation of extinction functions has been factored out into
a separate Python module called ``extinction``, which is now a dependency.

- ``Model.bandflux()`` and ``Source.bandflux()`` now integrate on a
fixed wavelength grid of 5 angstroms regardless of the wavelength
grid of the bandpass. This will result in small differences in
results from previous sncosmo versions.

- The internal (publicly undocumented) ``Spectrum`` class now acts
more like ``Model``; in particular, its ``bandflux()`` method now
behaves the same way. As ``Spectrum`` backs ``SpectralMagSystem``,
this makes the integration of models and zeropoint spectra more
consistent.

- Experimental (non-public) support for aliases for bandpasses,
such as ``'SDSS::g'`` for ``'sdssg'``.

- Sources now use cubic rather than quadratic spline interpolation internally.

- ``Model.source_peakmag()`` and ``Model.set_source_peakmag()`` added
as convenience functions for ``Model.source.peakmag()`` and
``Model.source.set_peakmag()`` respectively.

- **[Bugfix]** Fixed missing import of ``math`` module in ``mcmc_lc()``
when using the ``priors`` keyword. [Backported to v1.3.1]
[`143 <https://github.com/sncosmo/sncosmo/issues/143>`_]

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

This is mostly a bugfix release, but it also **drops support for Python 2.6.**
Python 2.7 is now the minimum supported Python version.

- Updates for compatibility with AstroPy 1.2.

- The registry now handles subclasses more robustly. For example,
if ``magsys`` is an instance of ``SpectralMagSystem``, the following
used to fail::

sncosmo.register(magsys, 'name')
sncosmo.get_magsystem('name')

Now this works. [`132 <https://github.com/sncosmo/sncosmo/issues/132>`_]

- **[Bugfix]** ``SALT2Source`` had a bug under Python 3 (only)
yielding drastically wrong fluxes. Python 2 was not affected. [`138
<https://github.com/sncosmo/sncosmo/issues/138>`_]

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

- **[API change]** Registry functions moved to the top-level namespace, as
follows:

- ``sncosmo.registry.register()`` -> ``sncosmo.register()``
- ``sncosmo.registry.register_loader()`` -> ``sncosmo.register_loader()``
- ``sncosmo.registry.retrieve()`` -> deprecated, use class-specific
functions such as ``sncosmo.get_bandpass()``.

The old import paths will still work for backwards compatibility.

- ``nest_lc()`` now uses the ``nestle`` module under the hood. A new
keyword ``method`` is available which selects different sampling
methods implemented by ``nestle``. The new methods provide potential
efficiency gains.

- The MLCS2k2 model is now available as a built-in Source, with the
name ``'mlcs2k2'``.

- Bandpasses from the Carnegie Supernova Project added to built-ins.

- In ``realize_lcs()``, a new ``scatter`` keyword makes adding noise
optional.

- **[Bugfix]** Fix built-in Bessell bandpass definitions, which were
wrong by a term proportional to inverse wavelength. This was due to
misinterpretation of the trasmission units. [backported to v1.1.1]
[`111 <https://github.com/sncosmo/sncosmo/issues/111>`_]

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

This is a mostly bugfix release with more solid support for Python 3.

- Added ``Model.color()`` method.

- Remove ``loglmax`` from result of ``nest_lc()``, which was not
officially documented or supported. Use ``np.max(res.logl)`` instead.

- Fixed bug that caused non-reproducible behavior in
``nest_lc()`` even when ``numpy.random.seed()`` was called
directly beforehand.
[`102 <https://github.com/sncosmo/sncosmo/issues/102>`_]

- Fixed file I/O problems on Python 3 related to string encoding.
[`83 <https://github.com/sncosmo/sncosmo/issues/83>`_,
`85 <https://github.com/sncosmo/sncosmo/issues/85>`_]

- Fixed problem with SDSS bandpasses being stored as integers internally,
preventing them from being used with models with dust.
[`100 <https://github.com/sncosmo/sncosmo/issues/100>`_,
`101 <https://github.com/sncosmo/sncosmo/issues/101>`_]

- Fixed problem where built-in source name and version strings were being
dropped. [`82 <https://github.com/sncosmo/sncosmo/issues/82>`_]

- Minor doc fixes.

exact results may differ between versions in the 1.x series. (For
example, due to changes in integration method.)

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

- **[API change]** The API of ``mcmc_lc`` has changed significantly
(the function was marked experimental in previous release).

- **[Deprecation]** In result of ``fit_lc``, ``res.cov_names`` changed to
``res.vparam_names``.

- **[Deprecation]** In result of ``nest_lc``, ``res.param_names``
changed to ``res.vparam_names``. This is for compatibility between
the results of ``fit_lc`` and ``nest_lc``.
[`30 <https://github.com/sncosmo/sncosmo/issues/30>`_]

- **[Deprecation]** Deprecate ``flatten`` keyword argument in
``fit_lc()`` in favor of explicit use of ``flatten_result()``
function.

- Many new built-in models.

- Many new built-in bandpasses.

- New remote data fetching system.

- SALT2 model covariance available via ``Model.bandfluxcov()`` method and
``modelcov=True`` keyword argument passed to ``fit_lc``.

- New simulation function, ``zdist``, generates a distribution of redshifts
given a volumetric rate function and cosmology.

- New simulation function, ``realize_lcs``, simulates light curve data given a
model, parameters, and observations.

- Add color-related keyword arguments to ``plot_lc()``.

- Add ``tighten_ylim`` keyword argument to ``plot_lc()``.

- Add ``chisq()`` function and use internally in ``fit_lc()``.

- Add ``SFD98Map`` class for dealing with SFD (1998) dust maps persistently so
that the underlying FITS files are opened only once.

- Update ``get_ebv_from_map()`` to work with new SkyCoord class in
``astropy.coordinates`` available in astropy v0.3 onward. Previously, this
function did not work with astropy v0.4.x (where older coordinates classes
had been removed).

- Update to new configuration system available in astropy v0.4 onward.
This makes this release incompatible with astropy versions less than
0.4.

- Now compatible with Python 3.

- Increased test coverage.

- Numerous minor bugfixes.