include/TabulatedRandomGenerator.h

#ifndef HZZ2L2NU_INCLUDE_TABULATEDRANDOMGENERATOR_H_
#define HZZ2L2NU_INCLUDE_TABULATEDRANDOMGENERATOR_H_

#include <limits>
#include <vector>

#include <TTreeReaderValue.h>

#include <Dataset.h>


class TabulatedRngEngine {
 public:
  using value_t = uint32_t;

  TabulatedRngEngine(Dataset &dataset);

  constexpr value_t MaxValue() const {
    return std::numeric_limits<value_t>::max();
  }

  value_t Read(int channel) const;

  int Register(int numChannels = 1);

 private:
  int numChannelsRegistered_;

  int const kSeed_ = 1439;

  int const kVolume_ = 100'000;

  std::vector<value_t> table_;

  mutable TTreeReaderValue<ULong64_t> event_;
};


class TabulatedRandomGenerator {
 public:
  TabulatedRandomGenerator(
      TabulatedRngEngine &engine, int numChannels = 1);

  double Gaus(int channel, double mean = 0., double sigma = 1.) const;

  double Rndm(int channel) const;

 private:
  TabulatedRngEngine &engine_;

  int numChannels_;

  int offset_;
};

#endif  // HZZ2L2NU_INCLUDE_TABULATEDRANDOMGENERATOR_H_

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