Pynbody

*This version ends support for Python 2.7, in favour of supporting Python 3.5, 3.6, 3.7 and 3.8*

The increase in the major version number reflects this, rather than the addition or change of any major functionality. Pip should automatically install older versions if you attempt to use pynbody with Python 2.7.

Bug fixes
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* Restores the Kravtsov and Hudson Stellar-Mass-Halo-Mass relations (bwkeller, 568)
* Fixes a bug with addition of dimensionless units (565)
* Fixes compatibility with Python 3.8

Bug fixes
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* Fix issue in fast_kde (519) where floating point numbers were accidentally used as an array sizze
* Compatibility fix for shared memory on macOS Catalina

Performance enhancement
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* Improve ramses reading times by reimplementing in Cython (cphyc, 548)

Features
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* Add option to write non-cosmological tipsy files (524)
* Improve ability of ramses reader to automatically run part2birth utility and use the results for a sensible `tform` array ( Martin-Rey, 520)
* Add support for AdaptaHOP halo finder (cphyc, 546)

Enhancements
===========

* Add a halo mass function analysis tool in `pynbody.analysis.hmf` (Martin-Rey)
* Add halo shape analysis tools (Matt Orkney)
* Introduce option to force gadget loader to use non-cosmological units (`ignore_cosmo=True`; elehcim)
* Add ability to use a custom CMD luminosity file in `pynbody.analysis.luminosity`
* Fix major performance issue with ramses files in Python 3.x (which arose due to the interaction between numpy and Python 3.x IO caching system)
* Increase number of fields read by the grafIC reader

Bug fixes
=======

* Allow use of AHF reader in read-only folders (issue warning instead of exception that cache cannot be written)
* Allow SPH smoothing to work even if units of box size are unknown
* Fix issue where IndexedSimArray with converted units could crash Python 3.x (elehcim)
* Compatibility fix for iteration in Python 3.7
* Fix issue where AHF load checking would ignore a specified `ahf_basename`, preventing `f.halos(ahf_basename='...')` from working
* Fix mismatched signature in AHF reader's `writehalos` method, which caused it to fail

*Enhancements:*
* Add default mapping for black holes in GadgetHDF snapshots
* Better dependency specification in `setup.py` for automated installation (rokroskar)
* Handles Eagle-like GadgetHDF snapshots which store their halo/group catalogue as two arrays (specifying the group and subgroup number)
* Add ability to save back individual arrays in GadgetHDF format using `snap['arname'].write()` or `snap.family['arname'].write()` syntax
* Performance enhancements to GadgetHDF implementation

*Bug fixes:*
* Fixed an issue where mu (relative atomic mass) was defined incorrectly in some cases (mtremmel / trquinn)
* Fixed an issue in IndexedSubSnap, where an entire family array could be incorrectly returned instead of an empty array when no family members were present in the IndexedSubSnap
* Fixed an issue where inconsistent smoothing information would prevent a KDTree from generating density estimates; now KDTree insists on using its own smoothing lengths to prevent this occurring.

Bug fixes
- Fixed RGB star rendering on Python 3
- Fixed bugs affecting isolated runs with Gadget

Enhancements
- Better handling of how "eps" (softening) is passed to gravity routines to avoid dtype mismatches
- Introduced option to use a .units file to override the default inferred units of a file (Michele Mastropietro)
- Made improved error message for when a multi-threaded image rendering goes wrong on one or more threads

New features
- NFW profile fitting, with a framework for fitting other generic profiles (by Martin Rey)
- Halo shape fitting (by Matt Orkney)

* Reads Rockstar catalogues
* Refactors halo module into a subpackage for better readability and maintainability
* Improved GadgetHDF versatility