Accessing member functions from a tree

From: Mark Boulay (mgb@phy.queensu.ca.cern.ch)
Date: Mon Jun 15 1998 - 18:09:12 MEST


Hello all,

I'm trying to access a member function of a class which I've
used to generate a tree:

For example, if I have a class Event, which contains data members X,Y, and
Z, and a member function GetR(), with

{
Event *event;
TTree *tree = new TTree("T","event tree");
tree->Branch("Events","Event",&event,2000,1);
event = new Event();
for (Int_t i=0; i<100; i++)
{
	event->SetX( (Float_t)i );
	event->SetY( (Float_t)2*i );
	event->SetZ( (Float_t)3*i );
	tree->Fill();
}


I would then like to use the TTree->Draw() command with something
like:
tree->Draw("Events.GetR()");

I can do this only if GetR() does not access any of the data members
of the event class, otherwise I get a segmentation violation.

Any 'pointers'?

Thanks, Mark.

=================================================================
=                                                               =
= Mark Boulay                                                   =
= SNO Project                                                   =
= Department of Physics   phone/voice mail: (613) 545-6861      =   
= Queen's University      fax: (613) 545-6813                   =
= Kingston, Ontario       email: mgb@owl.phy.queensu.ca         =             
= Canada, K7L 3N6                                               =
=                                                               =
=================================================================



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