v1.10.0

New Features

• wcs1d-fits loader now reads and writes celestial components of
  of multi-dimensional WCS, and handles mask and uncertainty
  attributes. [#1009]

• Added support for reading from files with flux in counts. [#1018]

Bug Fixes

• Fixed SpectralAxis.with_observer_stationary_relative_to to actually
  return the updated spectral axis. [#992]

• Fixed region extraction for axes/regions in units of u.pix. [#1001]

• tabular-fits writer now properly converts uncertainties to StdDevUncertainty
  if needed. [#1027]

• Fix bug in fit_lines which gave unexpected outputs from the get_fit_info
  and ignore_units keyword arguments. [#1030]

• Fix SNR calculations with both masks and regions. [#1044]

Other Changes and Additions

• Added some basic documentation for Spectrum1D.write. [#1017]

• JWST s2d and s3d readers now requires the optional dependency, stdatamodels,
  which user has to install separately. [#1038]

• ASDF tag for Spectrum1D is now compatible with ASDF v3.
  As a result, minversion of asdf has been bumped to 2.14.
  Redundant ASDF schema for SpectralCoord is removed.
  It also now supports mask serialization. [#1042, #1053]

• JWST X1D reader will no longer raise a UnitWarning for surface brightness
  error. [#1050]

v1.9.1

Bug Fixes

• Add and subtract operations on Spectrum1D now allow for other operand's class
  to handle the arithmetic if that class has special handling. [#988]

v1.9.0

Bug Fixes

• Fix bug in fitting with weights if weights argument is set to 'unc'. [#979]
• Fix bug in JWST reader which caused multi-extension files to load only the
  primary HDU [#982]
• Implemented conversion to expected uncertainty type in a few functions that
  were still just assuming the uncertainty was the correct type. [#984]

Other Changes and Additions

• Bumped astropy minimum version to 5.1. [#984]

V1.8.1

Bug Fixes

• Arithmetic with constants and Spectrum1D now works in either order. [#964]

• Fixed uncertainty propagation in FluxConservingResampler. [#976]

V1.8.0

New Features

• Implemented uncertainty propagation for analysis functions. [#938, #939, #961, #968]

• Model fitting with fit_lines now returns uncertainties from the underlying scipy
  fitter by default. [#962]

Bug Fixes

• Fixed a bug with moment map orders greater than 1 not being able to handle
  cubes with non-square spatial dimensions. [#970]

• Added a workaround for reading JWST IFUs with incorrect GWCS. [#973]

Other Changes and Additions

• The Spectrum1D redshift and radial_velocity attribute setters were deprecated
  in favor of the more explicit set_redshift_to, shift_spectrum_to, and
  set_radial_velocity_to methods. [#946, #943]

• estimate_line_parameters now calculates estimates based on the selected
  region, rather than the entire spectrum. [#962]

V1.7.0

Bug Fixes

• Fixed spectral_slab crashing when spectral_axis has unit of pixels and
  the bounds are also defined in the unit of pixels. [#926]

• Fixed resulting spectral_axis containing NaN when a cube is passed into
  Spectrum1D without WCS nor spectral axis and the spatial-spatial dimension
  is smaller than spectral dimension. [#926]

• Fixed WCS not accurately reflecting the updated spectral axis after slicing a
  Spectrum1D. [#918]

Other Changes and Additions

• Logger usage is removed. Warnings now issued using Python warnings module.
  This enables more granular warning control for downstream packages. [#922]

V1.6.0

New Features

• Added collapse methods to Spectrum1D (mean, median, max, min, sum). [#904, #906]

• SpectralRegion and Spectrum1D now allow descending (in wavelength space) as
  well as ascending spectral values. [#911]

V1.5.0

New Features
^^^^^^^^^^^^

• Convolution-based smoothing will now apply a 1D kernel to multi-dimensional fluxes
  by convolving along the spectral axis only, rather than raising an error. [#885]

• template_comparison now handles astropy.nddata.Variance and
  astropy.nddata.InverseVariance uncertainties instead of assuming
  the uncertainty is standard deviation. [#899]

Bug Fixes
^^^^^^^^^

• Speed up JWST s3d loader and reduce memory usage. [#874]

• SpectralRegion can now handle pixels. [#886]

• Fix bug where template_comparison would return the wrong chi2 value. [#872]

Other Changes and Additions
^^^^^^^^^^^^^^^^^^^^^^^^^^^

• fit_lines now makes use of unit support in astropy.modeling. [#891]

• Spectrum1D.with_spectral_units now attempts to fall back on the spectral_axis
  units if units could not be retrieved from the WCS. [#892]

• ndcube package pin updated to released version (2.0). [#897]

• Minor changes for astropy 5.0 compatibility. [#895]

V1.4.1

Minor bugfix release, see changelog.

v1.4.0

See change log for list of new features and bug fixes.