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--- snowmass2013:analyse_d3 [2013/05/30 18:53]
127.0.0.1 external edit
+++ snowmass2013:analyse_d3 [2014/04/24 01:51] (current)
@@ Line 1: / Line 1: @@
 [[snowmass2013:montecarlo| <<back]]
-=== How to analyze Delphes3 ROOT files ===
+==== 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
+This example shows how to run a C+= program over all Delphes ROOT files located in  a certain directory, fill histograms (pT and jet mass) and save them in an output ROOT file.
-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]].
@@ Line 17: / Line 16: @@
-=== Advanced  Delphes3 example  ===
+==== Advanced C++ example  ====
 This assumes that Delphes3 is already installed. You have the directory "Delphes3" with the shared file "libDelphes.so" inside.
@@ Line 23: / Line 22: @@
 Get the analysis file: {{:snowmass2013:antup.tgz|}}
-<code>
+<code bash>
 tar -zvxf antup.tgz
 cd antup
@@ Line 29: / Line 28: @@
 So you will see 2 directories:
-<code>
+<code bash>
 delphes3
 antup
@@ Line 37: / Line 36: @@
 Now go to the directory "antup"  and link the existing  Delphes3 installation:
-<code>
+<code bash>
 ln -s  ../Delphes3  delphes
 </code>
@@ Line 43: / Line 42: @@
 In my case, it will look as:
-<code>
+<code bash>
 analysis.h
 A_RUN_TEST
@@ Line 55: / Line 54: @@
 Check that you see the shared Delphes3 file
-<code>
+<code bash>
 ls -l delphes/*so
 </code>
@@ Line 66: / Line 65: @@
 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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