04 - accessing clustering information in a PseudoJet

illustrate how a jet can carry information about its clustering

We do it by associating a user index to each of the input particles and show what particles are in each jets (above 5 GeV)

We also illustrate a few other features about how a fastjet::PseudoJet can access its underlying structure.

run it with : ./04-constituents < data/single-event.dat

Source code: 04-constituents.cc