First version of some Cornell code ported to run on RA2b's 41x Ntuples made by

TheNtupleMaker (https://twiki.cern.ch/twiki/bin/view/CMS/TheNtupleMaker).

Some important features of the original Cornell code are currently missing.
Resurrecting the use of the enums that ultimately specify which type of
collection to use for the various objects and whether or not to turn on various corrections
is important. We may also want to resurrect the class structure of the code.

This analyzer was created with tag v5_1_2 of UserCode/SusySapien/PhysicsTools/TheNtupleMaker.

The variables.txt file used in making the analyzer was created using an ntuple created with tag ngoodmuoc
of UserCode/SusyAnalysis/RA2b/Ntuples/RA2b2011v1 and tag v5_1_1 (I think...) of TheNtupleMaker.
Only the "Events" tree was included.
The file is located here:
/castor/cern.ch/user/s/ssekmen/RA2b2011v1/V00-01-03/QCD_Pt_170to300_TuneZ2_7TeV_pythia6_Spring11-PU_S1_START311_V1G1-v1_AODSIM/QCD_Pt_170to300_TuneZ2_7TeV_pythia6/ntuple_99_4_OhF.root.

I hope we can develop this code in a way that only BasicLoopTools (and maybe BasicLoopCU.cc) has to be modified.
The rest of the files are generated automatically by mkanalyzer.py, and it would be nice
to keep it that way (especially true for BasicLoopCU.h).

Author: kreis

BasicLoopCU.cc

@@ -0,0 +1,113 @@
+//-----------------------------------------------------------------------------
+// File:        BasicLoopCU.cc
+// Description: Analyzer for ntuples created by TheNtupleMaker
+// Created:     Fri Jun  3 16:38:31 2011 by mkntanalyzer.py
+// Author:      Ben Kreis
+//-----------------------------------------------------------------------------
+//#include "BasicLoopCU.h"
+#include "BasicLoopTools.h"
+
+#ifdef PROJECT_NAME
+#include "PhysicsTools/TheNtupleMaker/interface/pdg.h"
+#else
+#include "pdg.h"
+#endif
+
+using namespace std;
+//-----------------------------------------------------------------------------
+int main(int argc, char** argv)
+{
+  // Get file list and histogram filename from command line
+
+  commandLine cmdline;
+  decodeCommandLine(argc, argv, cmdline);
+
+  // Get names of ntuple files to be processed and open chain of ntuples
+
+  vector<string> filenames = getFilenames(cmdline.filelist);
+  itreestream stream(filenames, "Events");
+  if ( !stream.good() ) error("unable to open ntuple file(s)");
+
+  // Get number of events to be read
+
+  int nevents = stream.size();
+  cout << "Number of events: " << nevents << endl;
+
+  // Select variables to be read
+
+  selectVariables(stream);
+  cutflow(stream);
+  reducedTree(".", stream);
+
+
+  // The root application is needed to make canvases visible during
+  // program execution. If this is not needed, just comment out the following
+  // line
+
+  TApplication app("analyzer", &argc, argv);
+
+  /*
+	 Notes:
+	
+	 1. Use
+	   ofile = outputFile(cmdline.outputfile, stream)
+	
+	 to skim events to output file in addition to writing out histograms.
+	
+	 2. Use
+	   ofile.addEvent(event-weight)
+	
+	 to specify that the current event is to be added to the output file. If
+	 omitted, the event-weight is taken to 1.
+	
+	 3. Use
+	    ofile.count(cut-name, event-weight)
+	
+	 to keep track, in the count histogram, of the number of events passing
+	 a given cut. If omitted, the event-weight is taken to be 1. If you want
+	 the counts in the count histogram to appear in a given order, specify the
+	 order, before entering the event loop, as in the example below
+	 
+	    ofile.count("NoCuts", 0)
+		ofile.count("GoodEvent", 0)
+		ofile.count("Vertex", 0)
+		ofile.count("MET", 0)
+  */
+  
+  outputFile ofile(cmdline.outputfilename);
+
+  //---------------------------------------------------------------------------
+  // Declare histograms
+  //---------------------------------------------------------------------------
+
+
+
+  //---------------------------------------------------------------------------
+  // Loop over events
+  //---------------------------------------------------------------------------
+
+  for(int entry=0; entry < nevents; ++entry)
+	{
+	  // Read event into memory
+	  stream.read(entry);
+
+	  // Uncomment the following line if you wish to copy variables into
+	  // structs. See the header file BasicLoopCU.h to find out what structs
+	  // are available.
+	  // fillObjects();
+	  
+	  // ---------------------
+	  // -- event selection --
+	  // ---------------------
+
+
+	  // ---------------------
+	  // -- fill histograms --
+	  // ---------------------	  
+
+	}
+
+  stream.close();
+  ofile.close();
+  return 0;
+}