Organisation of data files

The nnpdf code needs to be able to handle a great deal of different options with regard to the treatment of both experimental data and theoretical choices. In the code, every effort has been made to keep experimental and theoretical parameters strictly separate. In this section we shall specify the layout of the nnpdf data directory. It is in this directory that all of the read-only data to be used in the fit are accessed. The data files is located in the nnpdf git repository, under the nnpdf_data package.

Experimental data storage

The central repository for CommonData in use by nnpdf projects is located in the nnpdf git repository at

nnpdf_data/nnpdf_data/commondata

where a separate CommonData file is stored for each Dataset with the filename format described in NNPDF’s dataset naming convention. The data is installed as part of the python package of nnpdf, all data files to be installed must have a .yaml extension.

Theory lookup table

In order to organise the various different theoretical treatments available, the theory definitions are saved in theory cards located in

nnpdf_data/nnpdf_data/theory_cards

in the form of yaml files. A new theory can be added by simply adding a new yaml file with the desired theory ID. The definition of the accepted and required parameters can be found at:

nnpdf_data/nnpdf_data/theorydbutils.py

The following lines will check whether a newly added theory can be read by validphys (change 700 by the id of your newly added theory).

from nnpdf_data import theory_cards
from nnpdf_data.theorydbutils import fetch_theory
theory = fetch_theory(theory_cards, 700)

A script is provided to give a brief overview of the various theory options available. It can be found at

nnpdf_data/nnpdf_data/disp_theory.py

and should be run without any arguments.

Theory options are enumerated by an integer TheoryID. The parameters of each theory option are described in the lookup table under the appropriate ID. The current available parameters are summarised in Theory parameter definitions.

Theory storage

Each theory configuration is stored as a gzip compressed tar archive with filename format

theory_<THEORYID>.tgz

and is stored at the location specified in the default nnprofile.yaml. For easy access, they can be downloaded through the vp-get utility. Each archive contains the following directory structure

theory_X/

-cfactor/

-fastkernel/

Inside the directory theory_X/cfactor/ are stored CFACTOR files with the filename format

CF_<TYP>_<FKNAME>.dat

where <TYP> is a three-letter designation for the source of the C-factor (e.g. EWK or QCD) and <FKNAME> is the FK-Table to which it should be applied.

Finally the FK tables themselves are stored in theory_X/fastkernel/ with the filename format

<FKNAME>.pineappl.lz4

Naturally, all of the FastKernel and C-factor files within the directory theory_X/ have been determined with the theoretical parameters specified in the theory lookup table under ID X.