Utilities/interface/SimpleHistogramGenerator.h

0001 #ifndef SimpleHistogramGenerator_H
0002 #define SimpleHistogramGenerator_H
0003
0004 /**
0005  * This class is a simpler version (less memory demanding but slightly
0006  * slower) of HistogramGenerator. provides a C++ version of the REMT package from
0007  * Ronald Kleiss.
0008  *
0009  * The method generate() generates random number according to the
0010  * histogram bin content.
0011  *
0012  * \author Patrick Janot
0013  * $Date: 16 July 2009 14:20 */
0014
0015 #include <vector>
0016
0017 class RandomEngineAndDistribution;
0018 class TH1;
0019 class TAxis;
0020
0021 class SimpleHistogramGenerator {
0022 public:
0023   /// Constructor that perform the necessary integration and inversion steps
0024   /// xmin and xmax are the generation bounds, n is the internal table size
0025   /// and iter is the number of iterations for the numerical part.
0026   SimpleHistogramGenerator(TH1* histo);
0027
0028   /// Default destructor
0029   virtual ~SimpleHistogramGenerator() {}
0030
0031   /// The random generation
0032   double generate(RandomEngineAndDistribution const*) const;
0033
0034   int binarySearch(const int& n, const std::vector<float>& array, const double& value) const;
0035
0036 private:
0037   /// Pointer to the histogram
0038   //TH1 * myHisto;
0039
0040   /// the axis
0041   //TAxis * theXaxis;
0042
0043   /// Number of bins
0044   int nBins;
0045
0046   // Limits of integration
0047   double xMin, xMax;
0048
0049   // Bin width
0050   double binWidth;
0051
0052   /// Integral
0053   std::vector<float> integral;
0054
0055   /// Number of entries
0056   double nEntries;
0057 };
0058 #endif