@@ -28,59 +28,12 @@ guiding document for spectroscopic development in the Astropy Project.
2828 development stage that some interfaces may change if user feedback and
2929 experience warrants it.
3030
31- Changes coming in version 2.0
32- =============================
33-
34- Specutils 2.0 has been in development for some time and is nearly ready for release.
35- The major changes that will affect users are detailed here in an attempt to prepare
36- users for the transition.
37-
38- The most visible change is that the `~specutils.Spectrum1D ` class will be renamed
39- to ``Spectrum `` to reduce confusion about multi-dimensional flux arrays being supported.
40- The current class name will be deprecated in version 2.1; importing the old name will
41- work but raise a deprecation warning until then. Version 1.20 implemented a ``Spectrum ``
42- class as a simple wrapper around `~specutils.Spectrum1D ` so that you may update your
43- code to the new class name now and avoid deprecation warnings when 2.0 releases. Note
44- that the new keyword arguments ``move_spectral_axis `` and ``spectral_axis_index `` being
45- introduced in 2.0 will be ignored in 1.x if used when initializing the ``Spectrum `` class.
46-
47- Single-dimensional flux use cases should be mostly unchanged in 2.0, with the exception
48- being that spectrum arithmetic will check that the spectral axis of both operands are
49- equal, rather than simply checking that they are the same length. Thus, you will need
50- to resample onto a common spectral axis if doing arithmetic on spectra with differing
51- spectral axes.
52-
53- Specutils version 2 implements a major change in that ``Spectrum ``
54- no longer forces the spectral axis to be last for multi-dimensional data. This
55- was motivated by the desire for greater flexibility to allow for interoperability
56- with other packages that may wish to use ``specutils `` classes as the basis for
57- their own, and by the desire for consistency with the axis order that results
58- from a simple ``astropy.io.fits.read `` of a file. The legacy behavior can be
59- replicated by setting ``move_spectral_axis='last' `` when creating a new
60- ``Spectrum `` object. ``Spectrum `` will attempt to automatically
61- determine which flux axis corresponds to the spectral axis during initialization
62- based on the WCS (if provided) or the shape of the flux and spectral axis arrays,
63- but if the spectral axis index is unable to be automatically determined you will
64- need to specify which flux array axis is the dispersion axis with the
65- ``spectral_axis_index `` keyword. Note that since the ``spectral_axis `` can specify
66- either bin edges or bin centers, a flux array of shape ``(10, 11) `` with spectral axis
67- of length 10 or 11 would be ambigious. In this case you could initialize a
68- ``Spectrum `` with ``bin_specification `` set to either "edges" or "centers"
69- to break the degeneracy.
70-
71- An additional change for multi-dimensional spectra is that previously, initializing
72- such a ``Spectrum `` with a ``spectral_axis `` specified, but no WCS, would
73- create a ``Spectrum `` instance with a one-dimensional GWCS that was essentially
74- a lookup table with the spectral axis values. In 2.0 this case will result in a GWCS with
75- dimensionality matching that of the flux array to facilitate use with downstream packages
76- that expect WCS dimensionality to match that of the data. The resulting spatial axes
77- transforms are simple pixel to pixel identity operations, since no actual spatial
78- coordinate information is available.
79-
80- In addition to the changes to the generated GWCS, handling of input GWCS will also be
81- improved. This mostly manifests in the full GWCS (including spatial information) being
82- retained in the resulting ``Spectrum `` objects when reading, e.g., JWST spectral
83- cubes.
31+ Changes in version 2.0
32+ ======================
33+
34+ Specutils 2.0 has been released, see the stable docs for a summary of the changes.
35+ This version of the documentation will remain available for user of ``specutils `` 1.x.
36+
8437
8538Getting started with :ref: `specutils <specutils >`
8639=================================================
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