A++ Reference Guide

The A++ framework is made for the offline analysis of ATLAS events. It mainly consists of two parts:

1. The A++ converter which converts AOD or ESD information into A++ .root files. The converter is not described in this document.
2. The A++ event classes and class libraries for the analysis of A++ events. These classes are the content of this documentation.

The main class for the event data model is the AtlEvent class which describes a full ATLAS proton-proton collision event. Beside the event header (AtlEventHeader) and the trigger information (AtlTrigger), an A++ event object contains mostly lists of reconstructed and truth objects like jets (AtlJet), elctrons (AtlElectron), inner detector tracks (AtlIDTrack) or MC truth particles (HepMCParticle).

A++ event files are being processed by descendents of the AtlSelector class in order to fill histograms etc. Every analysis is performed by an analysis class which inherits from AtlSelector and provides user-defined functions for booking and filling histograms etc. See the class AtlExampleAnalysis" as an example.

Chapters

Class Index

A complete list of all classes defined in A++

Class Hierarchy

A hierarchy graph of all classes, showing each class's base and derived classes

Type Index

A complete list of all types

Library Dependency

A diagram showing all of A++'s libraries and their dependencies