Re: [ROOT] Draw command using branches located separate trees.

From: Andre Holzner (Andre.Holzner@cern.ch)
Date: Thu Apr 05 2001 - 11:20:57 MEST


Hello,

Rene Brun wrote:
> 
> Hi Malcolm,
> Currently, you cannot correlate variables from different Trees
> in the TTree::Draw function. This possibility will be included
> in the next Root release scheduled for June.

This sounds quite interesting to me ! (I would have liked to
have such a possibility in the past e.g. for doing plots
of data events before vs. after reprocessing etc.)

> A new class (let's call it TJoinTree) will be available, eg:
>   TJoinTree jt("jt");
>   TTree *t1, *t2, *t3;
>   jt.Add(t1);
>   jt.Add(t2);
>   jt.Add(t3);
>   jt.Draw("var1:var2:var3")
> where var1, var2, var3 could be in any of t1,t2,t3.
> TJoinTree deriving from TTree will have the TTree functions available.

Which combinations of ntuple entries will one get in the Draw command ?
All possible combinations of the ntuple entries ?
e.g. like

 jt.Draw("t1.energy:t2.energy","t1.run_number == t2.run_number &&
t1.event_number == t2.event_number") 


?

best regards,

André


-- 
------------------+----------------------------------
Andre Holzner     | +41 22 76 76750 
Bureau 32 2-C13   | Building 32     
CERN              | Office 2-C13    
CH-1211 Geneve 23 | http://wwweth.cern.ch/~holzner/



This archive was generated by hypermail 2b29 : Tue Jan 01 2002 - 17:50:41 MET