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--- snowmass2013:analyse_d3 [2013/06/01 02:56]
asc [How to analyze in PyROOT]
+++ snowmass2013:analyse_d3 [2014/04/24 01:51]
@@ Line 1: / Line 1: @@
-[[snowmass2013:montecarlo| <<back]]
-==== How to analyze in C++ ====
-This example shows how to run a program over all files in a certain directory, fill histograms (pT and jet mass) and
-save histograms in an output ROOT file.
-Look at the workbook of Delphes3 [[https://cp3.irmp.ucl.ac.be/projects/delphes/wiki/WorkBook| Delphes3 workbook]].
-To get started, install Delphes. You  should see the library "libDelphes.so".  The you can browser the ROOT tree as:
-<code C>
-gSystem->Load("libDelphes");
-TFile::Open("delphes_output.root");
-Delphes->Draw("Electron.PT");
-TBrowser browser;
-</code>
-==== Advanced C++ example  ====
-This assumes that Delphes3 is already installed. You have the directory "Delphes3" with the shared file "libDelphes.so" inside.
-Get the analysis file: {{:snowmass2013:antup.tgz|}}
-<code bash>
-tar -zvxf antup.tgz
-cd antup
-</code>
-So you will see 2 directories:
-<code bash>
-delphes3
-antup
-</code>
-Now go to the directory "antup"  and link the existing  Delphes3 installation:
-<code bash>
-ln -s  ../Delphes3  delphes
-</code>
-In my case, it will look as:
-<code bash>
-analysis.h
-A_RUN_TEST
-data.in
-delphes -> ../Delphes3/
-main.cxx
-Make_input
-out
-</code>
-Check that you see the shared Delphes3 file
-<code bash>
-ls -l delphes/*so
-</code>
-You should see "delphes/libDelphes.so"
-The main file which fills histograms is "main.cxx". It fills some jet variables and save histograms in the ROOT file in "/out" directory.
-To run the code, run "./A_RUN_TEST" which loops over the existing ROOT files.
-But before you do this, you will need to set "DATA_DIR" variable inside "A_RUN_TEST" to navigate to the directory with your "ROOT" files.
-==== How to analyze in PyROOT ====
-If ROOT was compiled using "python" option, you can use PyROOT to loop over events. Here is a small example to plot transverse moment of electrons (based on the original code of Peter Onyisi, with some modifications, see
-[[https://indico.cern.ch/getFile.py/access?contribId=5&resId=0&materialId=slides&confId=255032| his talk]]):
-<code python test.py>
-#!/usr/bin/env python
-# Based on P.Onyisi example
-import sys,os,string
-if len(sys.argv)<2:
-    print "Usage: python test.py file.root"
-    print "Exit.."
-    sys.exit()
-from ROOT import *
-TH1D.SetDefaultSumw2()
-gSystem.Load('libDelphes.so')
-f=TFile(sys.argv[1])
-t=f.Delphes # extract the tree
-h=TH1D('ele','Electron #eta',8,-4,4) # initialize a histogram
-c1=TCanvas() # build a canvas
-n=0
-for e in t:   # loop over all events
-  if n%100==0: print "Event=",n
-  n=n+1
-  for electron in e.Electron: # loop over all electrons
-     h.Fill(electron.Eta)
-h.Draw()
-c1.Print('electron.pdf')
-if (raw_input("Press any key to exit") != "-9999"):
-    c1.Close(); sys.exit(1);
-</code>
-Run this code as:
-<code>
-python test.py file.root
-</code>
-You will see this image:
-{{:snowmass2013:screenshot_from_2013-05-31_21_55_04.png?200|}}
-====How to analyze in Java====
-MC truth information and most of ROOT files with Delphes outputs
- are stored in the PROMC file format which can be analyzed on any platform.
-Read this [[snowmass2013:analyse_d36_promc| this section]].
- --- //[[[email protected]|Sergei Chekanov]] 2013/03/13 10:23//

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