rf404_categories.C

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/// \file
/// \ingroup tutorial_roofit
/// \notebook -nodraw
/// Data and categories: working with RooCategory objects to describe discrete variables
///
/// \macro_code
/// \macro_output
///
/// \date July 2008
/// \author Wouter Verkerke
 
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooPolynomial.h"
#include "RooCategory.h"
#include "Roo1DTable.h"
#include "RooGaussian.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
#include <iostream>
using namespace RooFit;
 
void rf404_categories()
{
 
   // C o n s t r u c t    a   c a t e g o r y   w i t h   l a b e l s
   // ----------------------------------------------------------------
 
   // Define a category with labels only
   RooCategory tagCat("tagCat", "Tagging category");
   tagCat.defineType("Lepton");
   tagCat.defineType("Kaon");
   tagCat.defineType("NetTagger-1");
   tagCat.defineType("NetTagger-2");
   tagCat.Print();
 
   // C o n s t r u c t    a   c a t e g o r y   w i t h   l a b e l s   a n d   i n d i c e s
   // ----------------------------------------------------------------------------------------
 
   // Define a category with explicitly numbered states
   RooCategory b0flav("b0flav", "B0 flavour eigenstate");
   b0flav["B0"] = -1;
   b0flav["B0bar"] = 1;
   // Print it in "verbose" mode to see all states.
   b0flav.Print("V");
 
 
   // Alternatively, define many states at once. The function takes
   // a map with std::string --> index mapping.
   RooCategory largeCat("largeCat", "A category with many states");
   largeCat.defineTypes({
       {"A", 0}, {"b", 2}, {"c", 8}, {"dee", 4},
       {"F", 133}, {"g", 15}, {"H", -20}
   });
 
 
   // I t e r a t e,   q u e r y   a n d   s e t   s t a t e s
   // --------------------------------------------------------
 
   // One can iterate through the {index,name} pair of category objects
   std::cout << "\nThis is the for loop over states of 'largeCat':";
   for (const auto& idxAndName : largeCat)
     std::cout << "\n\t" << idxAndName.first << "\t" << idxAndName.second;
   std::cout << '\n' << std::endl;
 
   // To ask whether a state is valid use:
   std::cout <<   "Has label 'A': " << largeCat.hasLabel("A");
   std::cout << "\nHas index '-20': " << largeCat.hasIndex(-20);
 
   // To retrieve names or state numbers:
   std::cout << "\nLabel corresponding to '2' is " << largeCat.lookupName(2);
   std::cout << "\nIndex corresponding to 'A' is " << largeCat.lookupIndex("A");
 
   // To get the current state:
   std::cout << "\nCurrent index is " << largeCat.getCurrentIndex();
   std::cout << "\nCurrent label is " << largeCat.getCurrentLabel();
   std::cout << std::endl;
 
   // To set the state, use one of the two:
   largeCat.setIndex(8);
   largeCat.setLabel("c");
 
 
 
   // G e n e r a t e   d u m m y   d a t a  f o r   t a b u l a t i o n   d e m o
   // ----------------------------------------------------------------------------
 
   // Generate a dummy dataset
   RooRealVar x("x", "x", 0, 10);
   RooDataSet *data = RooPolynomial("p", "p", x).generate(RooArgSet(x, b0flav, tagCat), 10000);
 
 
   // P r i n t   t a b l e s   o f   c a t e g o r y   c o n t e n t s   o f   d a t a s e t s
   // ------------------------------------------------------------------------------------------
 
   // Tables are equivalent of plots for categories
   Roo1DTable *btable = data->table(b0flav);
   btable->Print();
   btable->Print("v");
 
   // Create table for subset of events matching cut expression
   Roo1DTable *ttable = data->table(tagCat, "x>8.23");
   ttable->Print();
   ttable->Print("v");
 
   // Create table for all (tagCat x b0flav) state combinations
   Roo1DTable *bttable = data->table(RooArgSet(tagCat, b0flav));
   bttable->Print("v");
 
   // Retrieve number of events from table
   // Number can be non-integer if source dataset has weighed events
   double nb0 = btable->get("B0");
   std::cout << "Number of events with B0 flavor is " << nb0 << std::endl;
 
   // Retrieve fraction of events with "Lepton" tag
   double fracLep = ttable->getFrac("Lepton");
   std::cout << "Fraction of events tagged with Lepton tag is " << fracLep << std::endl;
 
   // D e f i n i n g   r a n g e s   f o r   p l o t t i n g ,   f i t t i n g   o n   c a t e g o r i e s
   // ------------------------------------------------------------------------------------------------------
 
   // Define named range as comma separated list of labels
   tagCat.setRange("good", "Lepton,Kaon");
 
   // Or add state names one by one
   tagCat.addToRange("soso", "NetTagger-1");
   tagCat.addToRange("soso", "NetTagger-2");
 
   // Use category range in dataset reduction specification
   RooDataSet *goodData = (RooDataSet *)data->reduce(CutRange("good"));
   goodData->table(tagCat)->Print("v");
}