Tutorial

LCIO

LCIO is the event data model of Marlin and thus of MarlinTPC. It defines the data classes which are stored, for instance a lcio::TrackerHit , which is a reconstructed 3D hit with spatial coodrinates and the deposited charge. All these objects are derived from lcio::LCObject.

LCIO objects are stored in so called lcio::LCCollections.Each collection contains LCObject of a certain kind, for instance lcio::TrackerHits. Each collection has a user given name which should describe which sort of data is stored.

Examples:

• A collection with TrackerHits from the TPC is called TPCHits
• Another collecton, also containing TrackerHits but from a silicon hodoscope, whould be called HodoscopeHits
• A collection with lcio::Tracks from the TPC standalone reconstruction could be called TPCTracks, while the final tracks from both TPC and silicon hodoscope might be named Tracks

A lcio file consists of a sequence of lcio::LCEvents which contain all the collections which have been reconstructed.

Example:

Event Nr	Collection Name	Collection Type
1
	TPCHits	lcio::TrackerHit
	TPCTracks	lcio::Track
2
	TPCHits	lcio::TrackerHit
3
	TPCHits	lcio::TrackerHit
	TPCTracks	lcio::Track

The events don't necessarily have the same collections. In the second event for instance no tracks have been found, which means there is no TPCTracks collection.

Marlin

Reconstruction Work Flow

-- MartinKillenberg - 22 Jul 2008