---------- Forwarded message ----------
From: Martin Turner <martin@hep.ph.liv.ac.uk>
To: Rene Brun <Rene.Brun@cern.ch>
Date: Wed, 8 May 2002 21:59:59 +0100 (BST)
Subject: Leaves that are a dynamic array.
Hi Root experts. I'm afraid I stumbled across another problem. Hopefully
this will be quick.
I want to build arrays of variable size onto a single branch. What is
wrong with these code snippets:
fLambdaBfile = new TFile("LambdaB_analysis.root","recreate");
fLambdaB_tree = new TTree("LambdaB_analysis","lambdaB analysis tree");
fLambda_selection.fcandidate=10;//initialize size of the arrays to
something
fLambdaB_tree->Branch("Lambda_selection",&fLambda_selection,"fcandidate/I:==>
flambda_momx[fcandidate]/D:flambda_momy[fcandidate]:flambda_momz[fcandidate]:==>
ftrack_idi[fcandidate]/I:ftrack_idj[fcandidate]:ftrack_motheridi[fcandidate]:==>
ftrack_motheridj[fcandidate]:ftrack_granidi[fcandidate]:==>
ftrack_granidj[fcandidate]:fientry");
members are defined in the header file like this:
struct Lambda_selection{
Int_t fcandidate;
Double_t flambda_momx[10];
Double_t flambda_momy[10];
Double_t flambda_momz[10];
Int_t ftrack_idi[10],ftrack_idj[10];
Int_t ftrack_motheridi[10],ftrack_motheridj[10];
Int_t ftrack_granidi[10],ftrack_granidj[10];
Int_t fientry;
};
Lambda_selection fLambda_selection;
When defining the branch, if I replace [fcandidate] with [10] I don't have
a problem, just a lot of wasted memory. fcandidate never exceeds 10. At
the TTree::Branch the error is:
ERROR leaf:flambda_momx, len=10 and max=0
ERROR leaf:flambda_momy, len=10 and max=0
etc.
Putting fcandidate last on the list gives an "Illegal leaf" error. How do
I get round this without splitting my leaves onto seperate branches?
Thanks for yor help.
Martin
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