I am using the skeleton produced by TTree::MakeSelector to analyse some
MC from the kk generator. When I look at a certain branch from a tree
using both this (with no cuts added) and also by looking at it directly
using TBrowser (also with no cuts) I get totally different histograms. The Selector
method shows one sharp spike, whereas the TBRowser shows the correct broad
distribution (I have seen many examples of the plot being a broad
distribution rather than one spike). Here is the code I used in the
skeleton:
#define mark2_cxx
#include "mark2.h"
#include "TH2.h"
#include "TStyle.h"
#include "TCanvas.h"
void mark2::Begin(TTree *tree)
{
Init(tree);
TString option = GetOption();
gDirectory->Delete("qsquared");
qsquared = new TH1F("qsquared", "q squared, tau", 120, 0, 6);
}
Bool_t mark2::ProcessCut(Int_t entry)
{
return kTRUE;
}
void mark2::ProcessFill(Int_t entry)
{
b_had_mass->GetEntry(23);
qsquared->Fill(had_mass);
}
void mark2::Terminate()
{
gStyle->SetOptStat(11111);
TCanvas *c1 = new TCanvas("c1", "kk2 comparison with koralb", 10, 10,
800, 600);
c1->SetBottomMargin(0.15);
qsquared->GetXaxis()->SetTitle("Invariant Mass of tau");
qsquared->GetXaxis()->SetTitleOffset(1.4);
qsquared->Draw();
}
The above code is called mark2.C. In root I then do:
.x chain.C
where chain.C contains:
{
TChain chain("h5");
chain.Add("kk.root");
}
Finally I run the mark2.C with chain.Process("mark2.C") and get the
histogram drawn.
I also thought I should be able to do:
TFile kk("kk.root")
h5.Process("mark2.C")
where h5 is a TNuple, but this crashes. Is there a way to do this since
a chain seems unnecessary if you only have one root file you want to use.
I hope someone can spot my mistake.
Thanks,
Mark.
--
--------------------------------------------------------------------------------------------
Mark Hodgkinson phone (+44)(0)161 2754150
Office 7-11 email markhod@hep.man.ac.uk
HEP Group
Schuster Laboratory
University of Manchester
Oxford Road
Manchester
England
http://www.hep.man.ac.uk/~markhod
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