New Features and Important Changes in GammaLib 1.6.0

10 February 2018


1. Introduction
---------------
This document briefly summarizes module by module the most important changes
made since the last release of GammaLib.


2. Public interface modifications
---------------------------------
The following classes have been added:
- none

The following classes have been removed:
- none

The following classes have been renamed:
- none

The following methods have been added:
- gammalib::atan2()
- gammalib::plaw_integral()
- GSkyDir::cos_dist()
- GCTAInstDir::theta()
- GCTAInstDir::phi()
- GCTABackground::rate_ebin()
- GCTABackgroundPerfTable::rate_ebin()
- GCTABackground3D::rate_ebin()

The following methods have been removed:
- none

The following methods have been renamed:
- none

The arguments for the following methods have been changed:
- none

The return value of the following methods has been changed:
- none


3. Configuration
-----------------
None


4. Application module
---------------------
None


5. Base module
--------------
None


6. FITS I/O Interface
---------------------
None


7. Linear algebra module
------------------------
None


8. Model module
---------------
None


9. Numerics module
------------------
The gammalib::atan2() function was added to compute the arc tangens of a ratio
in radians (#2308).

The gammalib::plaw_integral() function was added to compute the area under a
power law between two boundaries (#2308).


10. Observation module
----------------------
None


11. Optimization module
-----------------------
None


12. Sky module
--------------
Add GSkyDir::cos_dist() method that computes the cosine of the angular distance
between two sky directions. Using this method avoids computation of the arc
cosine (#2309).


13. Support module
------------------
None


14. XML module
--------------
None


15. VO module
-------------
None


16. Xspec module
----------------
None


17. Test module
---------------
None


18. Multi-wavelength interface
------------------------------
None


19. Fermi-LAT interface
----------------------
None


20. CTA interface
-----------------
A GCTAInstDir::theta() and GCTAInstDir::phi() methods were added that return the
distance to the camera centre in radians and the azimuth angle, respectively (#2308).

A rate_ebin() method was added to the interface of the GCTABackground class and
implemented for the GCTABackgroundPerfTable and GCTABackground3D classes. The method
computes for a given instrument direction the background rate integrated over an
energy bin (#2308).


21. COMPTEL interface
---------------------
None