Difference between revisions of "Ntuple analysis skeleton"

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1) [http://www.nikhef.nl/~ivov/Analysis_Skeleton/simpleTTbarAnalysis.h simpleTTbarAnalysis.h]
 
1) [http://www.nikhef.nl/~ivov/Analysis_Skeleton/simpleTTbarAnalysis.h simpleTTbarAnalysis.h]
 +
 +
:The standard header file extended with the implementation of a few routine
 +
the user is not expected to change often
  
 
2) [http://www.nikhef.nl/~ivov/Analysis_Skeleton/simpleTTbarAnalysis.C simpleTTbarAnalysis.C]
 
2) [http://www.nikhef.nl/~ivov/Analysis_Skeleton/simpleTTbarAnalysis.C simpleTTbarAnalysis.C]
 +
 +
:The steering-file containing the location of the ntuples and a function that decides:
 +
:: o what ntuples to process
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:: o how many events to process
 +
:: o extension to the name of the output file
  
 
3) [http://www.nikhef.nl/~ivov/Analysis_Skeleton/simpleNtupleTTbarAnalysis.C simpleNtupleTTbarAnalysis.C]
 
3) [http://www.nikhef.nl/~ivov/Analysis_Skeleton/simpleNtupleTTbarAnalysis.C simpleNtupleTTbarAnalysis.C]
  
 
+
The user analysis-file where the user reads in the event, fills vectors with 'good'  
The file <font color = red>  simpleNtupleTTbarAnalysis.C </font> contains the location
+
physics objects (leptons, jets, photons etc. passing the user's quality requirements)
of the ntuples and the steering routines that decides:
+
and finally performs the top-analysis. The resulting histograms will be written out  
: o what ntuples to process
+
in a separate root file.
: o how many events to process
 
: o extension to the name of the output file
 
 
 
The file <font color = red>  simpleTTbarAnalysis.h </font> contains the header file and
 
implementation of a few routine the user is not expected to change often
 
 
 
The file <font color = red>  simpleTTbarAnalysis.C </font> is the file containing the
 
analysis code: read in the event, fill vectors with 'good' physics objects (leptons,  
 
jets, photons etc.) that passed the user's quality requirements and finally perform the  
 
analysis. The resulting histograms will be written out in a separate root file.
 
  
 
== Prescription ==
 
== Prescription ==

Revision as of 10:53, 30 June 2005

Analysis Skeleton to analyse the Standard Ntuple

The Analysis of the Root ntuple proceeds in a very straightforward way. Inside ROOT we used MakeClass() to get the .h and .C files. These were extended to our needs and together the following three files form the analysis skeleton:

1) simpleTTbarAnalysis.h

The standard header file extended with the implementation of a few routine
the user is not expected to change often

2) simpleTTbarAnalysis.C

The steering-file containing the location of the ntuples and a function that decides:
o what ntuples to process
o how many events to process
o extension to the name of the output file

3) simpleNtupleTTbarAnalysis.C

The user analysis-file where the user reads in the event, fills vectors with 'good' physics objects (leptons, jets, photons etc. passing the user's quality requirements) and finally performs the top-analysis. The resulting histograms will be written out in a separate root file.

Prescription

After setting the correct location of your ntuples in the file simpleNtupleTTbarAnalysis.C open a root session and do:

1) .L simpleTTbarAnalysis.C++;

2) .x simpleNtupleTTbarAnalysis.C(1,100,"test");

This will results in the analysis of the first 100 events in the ntuple-set 1.
 The histograms from the analysis will be stored in the file called 
 summary_ttbar_full_test.root