Re: axis range

Rene Brun (Rene.Brun@cern.ch)
Fri, 30 Apr 1999 15:45:18 +0200 (METDST)


You must do the following
Int_t nentries = tree->GetEntries();
tree->SetEstimate(nentries);
One statement should normally work. I have reported the problem to Masa.

Rene Brun

On Fri, 30 Apr 1999, Stephen Markacs wrote:

>
> Fons,
>
> I went to this page and tried t->SetEstimate(t->GetEntries()) and it won't
> let me call GetEntries in the argument:
>
> nevis1:emcal/calib> root -l
> *******************************************
> * *
> * W E L C O M E to R O O T *
> * *
> * Version 2.20/06 17 December 1998 *
> * *
> * You are welcome to visit our Web site *
> * http://root.cern.ch *
> * *
> *******************************************
>
> CINT/ROOT C/C++ Interpreter version 5.13.83, Dec 2 1998
> Type ? for help. Commands must be C++ statements.
> Enclose multiple statements between { }.
> root [0] f = new TFile("emcBeam.root")
> (class TFile*)0x0
> root [1] f->ls()
> TFile** emcBeam.root
> TFile* emcBeam.root
> KEY: TTree t;1 test beam data for timing studies
> root [2] t->SetEstimate(t->GetEntries())
> Error: No symbol t->GetEntries() in current scope FILE:/var/tmp/daaa006P_
> LINE:1
> *** Interpreter error recovered ***
> root [3] int N = t->GetEntries()
> root [4] t->SetEstimate(N)
> root [5] .q
>
> Is this something wierd that has been fixed in the newer versions of root?
>
>
> > Hi Seng,
> >
> > your question is answered here:
> >
> > http://root.cern.ch/root/roottalk/roottalk99/0566.html
> >
> > Cheers, Fons.
> >
> >
> >
> > Woon-Seng Choong wrote:
> > >
> > > Hi,
> > > I encountered a peculiar problem when using TTree::Draw. I have a tree
> > > which has a variable, say var, which range from 2172 to 2179. There are
> > > about 10 million events. I used the following command to plot the var:
> > >
> > > root [1] tree->Draw("var")
> > >
> > > What I got was a plot which range from 2171 to 2173 and has an overflow
> > > over 8 million events. Why didn't it draw the whole range?
> > > I am using ROOT v2.21/08.
> > >
> > > Seng
> >
> > --
> > Org: CERN, European Laboratory for Particle Physics.
> > Mail: 1211 Geneve 23, Switzerland
> > E-Mail: Fons.Rademakers@cern.ch Phone: +41 22 7679248
> > WWW: http://root.cern.ch/~rdm/ Fax: +41 22 7677910
> >
>
>
> S t e p h e n M a r k a c s
> stephen@phys.columbia.edu
> http://phys.columbia.edu/~stephen/
>