Hi Mark,
Why do you do:
b_had_mass->GetEntry(23);
it should be:
b_had_mass->GetEntry(entry);
Rene Brun
Mark Hodgkinson wrote:
>
> 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
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:50:47 MET