Some of the changes introduced in release v2.1.9 were not backward compatible. This release makes those changes backward compatible.
2.1.9
===================
Compatibility improvements with Python 3 and other STScI software packages.
2.1.8
===================
- Drizzlepac code will no longer attempt to delete "original" (WCS key 'O') resulting in a decreased number of warnings (see `issue 35 <https://github.com/spacetelescope/drizzlepac/issues/34>`_ ).
- Negative values are now zeroed in the 'minmed' step before attempting to estimate Poisson errors (see `issue 22 <https://github.com/spacetelescope/drizzlepac/issues/22>`_).
- Fixed a bug in ``tweakreg`` due to incorrect matrix inversion.
- Improved compatibility with `astropy.io.fits` ('clobber' parameter) and `numpy` which has reduced the number of deprecation warnings).
- Existing static masks in the working directory are now overwritten and not simply re-used (see `issue 23 <https://github.com/spacetelescope/drizzlepac/issues/23>`_).
- Corrected formula for :math:`\sigma` computation in the "create median" step to convert background to electrons before computations. This bug was producing incorrect :math:`\sigma` for instruments whose gain was different from one.
- Improved ``astrodrizzle`` documentation for ``combine_type`` parameter which now also documents the formula for :math:`\sigma` computation when ``combine_type`` parameter is set to ``'minmed'``.
2.1.6
===============================
Package maintenance release.
2.1.5
===================
Technical re-release of ``v2.1.4``.
2.1.4
===================
The following bug fixes have been implemented:
- ``tweakreg`` crashes when run with a single input image and a reference catalog.
- Fixes an issue due to which ``tweakreg``, when updating image headers, would not add '-SIP' suffix to CTYPE