Now, I thought i knew how to make trees with variable length branches:
Int_t nPhot;
Float_t E[500];
Float_t Px[500];
Float_t Py[500];
Float_t Pz[500];
Float_t Arm[500];
Float_t PhotProb[500];
TTree* nEmcPhotons = new TTree("nEmcPhotons","EMC Photons");
nEmcPhotons->Branch("nPhot",&nPhot,"nPhot/I");
nEmcPhotons->Branch("E",E,"E[nPhot]/F");
nEmcPhotons->Branch("Px",Px,"Px[nPhot]/F");
nEmcPhotons->Branch("Py",Py,"Py[nPhot]/F");
nEmcPhotons->Branch("Pz",Pz,"Pz[nPhot]/F");
nEmcPhotons->Branch("Arm", Arm,"Arm[nPhot]/F");
nEmcPhotons->Branch("PhotProb", PhotProb,"PhotProb[nPhot]/F");
now when i Fill() this tree and save it to a file and then try and read it
back
and Draw() any of the variable-length fields, i get:
root [0] TFile f("nEmcPhotons.root")
root [1] nEmcPhotons->Draw("Pz")
Warning in <MakeDefCanvas>: creating a default canvas with name c1
Warning in <TBranch::GetBasket>: Estimated keylen too small=15697
Fatal in <operator new>: storage exhausted
aborting
making bufsize=128000 in the Branch() calls does not help...
- Peter