Re: Draw ves Project

From: Jean-Eric Campagne <campagne_at_lal.in2p3.fr>
Date: Wed, 08 Jun 2005 12:47:40 +0200

Cher Rene,

I am using ROOT 4.04/02 31may05

I have put on the Web <http://opera.web.lal.in2p3.fr/temporaire/> the file Pb.tgz

There are a pb.C macro and the (quite large) ROOT File with the TTree.

Jean-Eric

--On mercredi 8 juin 2005 12:09 +0200 Rene Brun <brun_at_pcroot.cern.ch> wrote:

> Jean-Eric,
>
> I cannot reproduce this problem.
> Note that TTree::Project calls TTree::Draw. So, I do not see why the
> output should be different.
> Please:
> -tell us which version of ROOT?
> -send the shortest possible script with a file repducing your problem
>
> Rene Brun
>
> On Wed, 8 Jun 2005, Jean-Eric Campagne wrote:
>
>> Dear developpers
>>
>> I have done the following
>> 1) open a ROOT file with a TTree which contains "zp" and "pdg" as
>> variables 2) do the tree drawing
>> tree->Draw("zp","pdg==211")
>> Then just to show for student an other possibility
>> 3) create a TH1D* h1 with ("h1","z prod of pi+",100,0,100)
>> 4) project the tree on h1 as followed
>> tree->Project(h1->GetName(),"zp","pdg==211")
>> 5) draw the result
>> h1->Draw("SAME")
>>
>> To my great surprise the 2 plots does not fit each other (see pb.ps
>> attached), and this is not just bin to bin fluctuation
>> Have you an idea?
>> Regards
>> Jean-Eric
>>
>>
>> ........................................................................
>> ... .LAL - IN2P3 - CNRS
>> .LAL - B.P 34 - 91898 Orsay Cedex - France
>> .Piece 108
>> .Tel +33 (0)1 64 46 84 29
>> .Fax +33 (0)1 64 46 83 97
>> ........................................................................
>> ...
>>
>>

...........................................................................
.LAL - IN2P3 - CNRS
.LAL - B.P 34 - 91898 Orsay Cedex - France
.Piece 108
.Tel +33 (0)1 64 46 84 29

.Fax +33 (0)1 64 46 83 97

...........................................................................

Received on Wed Jun 08 2005 - 12:47:47 MEST