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sherpa/sherpa: Sherpa 4.11.0

Doug Burke; Omar Laurino; dtnguyen2; Jamie Budynkiewicz; Tom Aldcroft; Aneta Siemiginowska; Christoph Deil; wmclaugh; Brigitta Sipocz; Katrin Leinweber

Sherpa 4.11.0

Optimization routines and statistic methods were made more robust with several bug fixes and improvements.

This version of Sherpa has been tested with Python 2.7, 3.5, 3.6, and 3.7. Support for Python 2.7 is being deprecated and may be dropped in future releases.

This release also provides support for XSPEC 12.10.1 (patch 'a' or later) in addition to versions 12.10.0 (included in CIAO) and version 12.9.1.


Documentation and infrastructure fixes are not shown.

444 Improve caching
When fitting multiple datasets simultaneously Sherpa now tries to cache

model evaluations to improve performance.

465 Support XSPEC 12.10.0 (fix #436)
XSPEC 12.10.0e is now supported
508 Ensure fields are initialized before use (pileup code)
Resolved an issue where some fields in the C++ extension could have been

uninitialized in a corner case.

523 Ensure the ui modules have a unique list of exported symbols (fix #502)
Remove the `sherpa.utils.erf` symbol from the two `ui` modules as it is

"over-written" by the ModelWrapper-created symbol when applied to sherpa.models.basic.Erf.

524 Be explicit about 'invalid escape characters' in strings
Convert strings that contain "invalid" escape characters, which newer

versions of Python complain about, to raw strings by preceding them with a 'r' character.

525 Fixed based line radpro_dm test and changed double --> real (template) 530 Ensure XSPEC 12.10.0 uses ATOMDB 3.0.9 by default
Ensure that the default AtomDB version is 3.0.9 when using XSPEC 12.10.0.

This is to fix an issue with the models-only XSPEC installation in XSPEC 12.10.0 which uses a default version of 3.0.7 but only provides data files for 3.0.9. Without this change models such as XSapec would return all 0's (unless the AtomDB version was set manually by the user).

534 XSPEC 12.10.1 support and mtable fix
Sherpa now supports XSPEC 12.10.1. Several issues were fixed to ensure

compatibility with this release. Note that there are known issues with version 12.10.1 (no patches), so at least v12.10.1a must be used.

537 / #552 sherpa.rc changes
Sherpa does not read the verbosity.level setting from sherpa.rc anymore but

the option is still in the file for backward compatibility

539 Fix XSPEC models: mtable table models and ismabs (fix #535, #538, #540)
Fix to address issues with XSpec- #535 XSPEC multiplicative table models

(mtable models loaded with load_xstable_model); #538 incorrect evaluation of the ismabs model; #540 the kerrd model evaluated to 0 for XSPEC 12.10.0 and later.

546 Small code cleanup in LevMar
small code cleanup in the LevMar class to match the other classes in that


564 / #567 Harmonise the handling of dof is zero or negative in fit and calc_stat_info (fix #565)
The `fit` and `calc_stat_info` methods now use the same code to calculate

the reduced statistic (rstat) and "quality of fit" (qval) values. This avoids a TypeError when the number of degrees of freedom is negative in calc_stat_info and ensures that NaN is returned for both values when the goodness-of-fit calculation has failed (e.g. the reduced statistic is zero or less or the statistic is negative), whereas in previous versions the qval value could be None or 1 depending on the code path.

576 Fix regression with responses get_x method
Version 4.10.1 introduced a regression which made the `get_x()` method fail

when called on RMF and ARF objects. This has been resolved.

583 Update pager code (fix #445 #561)
Replace the use of an external pager (such as `more` or `less`) with a

Python one. This means that Sherpa no-longer uses the PAGER environment variable, and that the screen output from the show_* series of commands should now appear in the correct location when using a Jupyter notebook or the spyder application.

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