Getting Started with xAOD

This section of the FuncADL documentation will cover:

  • How to set up the environment to access xAOD data in ATLAS

  • Access methods, attributes, and decorations on the xAOD Event Data Model (EDM).

This section assumes you have the following prerequisite knowledge:

  • You have all the knowledge outlined in the ServiceX User Guide

  • Basic knowledge of the ATLAS xAOD data model (at the level of a standard ATLAS tutorial)

  • The names of the xAOD collections you are interested in, etc.

See also

If you have not worked through it please see the ServiceX User Guide to get foundational knowledge or ServiceX before completing this user guide.

This User Guide will give an understanding of how to build the queries that are passed to ServiceX.

FuncADL xAOD Releases

Depending on what ATLAS release is needed, it is required to install and import different libraries. The libraries are:

  • func_adl_servicex_xaodr21

  • func_adl_servicex_xaodr22

  • func_adl_servicex_xaodr25

These can be installed using pip.

Importing Query Function

All of the queries that are built in this user guide use a function to start the base query with. You can import the function that gives that base query like this:

from func_adl_servicex_xaodr25 import FuncADLQueryPHYSLITE, FuncADLQueryPHYS

The correct release and type of data will need to be selected.