Michael Mayer / gammalib

…ients argument (#1847)

The eval_gradients() methods duplicate much of the code of the eval() methods. To increase the maintainability of the code, the eval_gradients() methods have been removed, and the computation of partial derivatives is now done by the eval() methods if the optional gradients argument is set to true.

It seems better to not introduce the alias method but to use a type constructor instead. This allows writing out the same model type that was read in, enhancing the compatibility with the legacy XML format.

The following new names have been introduced for the spatial model components:
* "PointSource" (alias: "SkyDirFunction")
* "RadialDisk" (alias: "DiskFunction")
* "RadialGaussian" (alias: "GaussFunction")
* "RadialShell" (alias: "ShellFunction")
* "EllipticalDisk"
* "EllipticalGaussian" (alias: "EllipticalGauss")
* "DiffuseIsotropic" (alias: "ConstantValue")
* "DiffuseMap" (alias: "SpatialMap")
* "DiffuseMapCube" (alias: "MapCubeFunction")

…d. This is needed to provide correct results for cubes that are larger than the ROI.

These methods allow saving a spatial diffuse cube into a FITS file or FITS object.

set_mc_cone() called fetch_cube() which itself called load() which itself called set_mc_cone() with a larger cone again. This led to a neverending recursion.

I now introduced a load_cube() method that does the proper loading and that does not call set_mc_cone() again. This method is now used in fetch_cube().

… (blocking has been recognized using the ctobssim unit test).

The map cube is now only loaded when its values should be accessed.

The coding and design conventions (CDC) document was also updated.

All methods returning a solid angle are now named solidangle().

The GSkyPixel class now handles 1D and 2D sky indices. This made the distinctive 1D and 2D methods in GSkyProjection and the derived classes obsolete. Now, all projection classes take GSkyPixel as argument.

The GSkymap class now uses the universal GSkyPixel class. Methods have been renamed consistently. An integer index is now consistently called "sky map index" and the GSkyPixel object is named a "sky map pixel". Methods operating on indices contain now "inx", method operating on sky map pixels "pix".

A consistent radius should be used for MC cache setup and flux computation, otherwise there is a risk that the simulated data differ from the model in overall normalisation.

A contains() method has been added to GCTARoi that checks whether an event in contained within the ROI. This method will become pure virtual in the GRoi class later so that the check can be done independently of the ROI specifications.

The contains() method is now used in GCTAModelBackground for checking whether an event lies within the ROI.

The GCTAInstDir class now only has the dir() method to access and modify the GSkyDir member. All methods that were basically copied from GSkyDir have now been removed to avoid code duplication. Using the dir() method, all methods are now directly accessible from the GSkyDir object.

…ky directions returned by mc() to all pixels that touch a circular region. In addition, only pixels of which the centre falls within the circular region are considered for determining the spectral node function.

Note that this method affects the Monte Carlo cache.