APFELcomb is the project that allows the user to generate
FK tables. These
are lookup tables that contain the relevant information to compute theoretical
predicitons in the NNPDF framework. Broadly speaking, this is achieved by
taking DGLAP evolution kernels from
APFEL and combining them with
interpolated parton-level observable kernels of various forms. The mechanism
behind APFELcomb is presented in arXiv:1605.02070.
APFELcomb is available from
The various data formats used in APFELcomb are described in Experimental data files.
APFELcomb depends on the following libraries
and data files from
There are various ways of generating the latter, as explained in How to generate applgrids.
Once the above libraries and data files are set up, the APFELcomb project can be compiled as follows
Compilation flags and various paths are defined in
Makefile.inc. These are
mostly inferred from
<package>-config files with the exception of
./results) Defines the path results are written to.
../applgrids) Defines the path to the
.db) Defines the path to the APFELcomb database.
The defaults are configured assuming that both the
repositories are located at
FK table is generated piecewise in one or more
implemented in APFELcomb can be displayed by running the script
Typically DIS and
FKGenerator DY tables are made of only one subgrid, whereas
FK tables generated from APPLgrids have one subgrid per APPLgrid file.
How subgrids are merged into grids, and the generation parameters of each
subgrid, is specified in the
db/apfelcomb.db database. The database itself
is not stored in the repository, but it is built from the sqlite dump at
db/apfelcomb.dat. This is done automatically by the APFELcomb makefile.
Detailed instructions to generate/implement
FK tables for individual
experiments and/or a compelte theory are provided in
How to generate/implement FK tables.