Friday, December 14, 2018

Sherpa 4.10.2 bugfix release

Sherpa 4.10.2  has now been released and is available via our Conda channel (https://conda.anaconda.org/sherpa), pip (https://pypi.python.org/pypi/sherpa/4.10.2), Zenodo (https://zenodo.org/record/2275738#.XBPp81WYUeM), and GitHub (https://github.com/sherpa/sherpa/tree/4.10.2).

This release supports Python versions 2.7, 3.5, 3.6, and 3.7.

We thank everyone who contributed to this release with feature requests, bug reports, testing, code
contributions, or questions.  Please join in the fun on GitHub: https://github.com/sherpa/sherpa/

The documentation for this release can be found at https://sherpa.readthedocs.io/en/4.10.2/

OVERVIEW

This release fixes a regression introduced in Sherpa 4.10.1 that was noted by the GammaPy team. As part of the long term PSF rebinning improvements, Sherpa 4.10.1 introduced a check to validate that the data pixel size and the PSF pixel size match. If they don't match, then a warning is issued. The change did not account for an edge error case. Sherpa 4.10.2 solves this problem.

Details

#551 Fix gammapy/gammapy#1905, catch errors with psf pixel size.

Sherpa did not properly catch errors when checking the PSF pixel size matches the image pixel size. This has now been fixed.

Caveats

There is a potential issue for macOS conda users with python > 3.6 and matplotlib v3.0.1, when pyqt5 is not installed and selected as a matplotlib backend. With this specific combination of platform and dependencies, matplotlib can fail to work properly (rhe issue can be replicated without importing Sherpa, so this is not a Sherpa bug).

Several workarounds exist, the simplest of which are:

  • install pyqt5 (conda install pyqt`).
  • downgrade matplotlib to v2 or v3.0.0 (conda install matplotlib=3.0.0)