//                                               -*- C++ -*-
/**
 *  @file  t_RandomGenerator_std.cxx
 *  @brief The test file of class RandomGenerator for standard methods
 *
 *  Copyright (C) 2005-2013 EDF-EADS-Phimeca
 *
 *  This library is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  along with this library.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  @author schueller
 *  @date   2012-02-17 19:35:43 +0100 (Fri, 17 Feb 2012)
 */
#include "OT.hxx"
#include "OTtestcode.hxx"

using namespace OT;
using namespace OT::Test;

int main(int argc, char *argv[])
{
  TESTPREAMBLE;
  OStream fullprint(std::cout);

  try
    {
      // Test the initialization method
      RandomGenerator::SetSeed(0);
      // Test the state accessor for reading
      RandomGeneratorState initialState(RandomGenerator::GetState());
      fullprint << "state index=" << initialState.index_ << " state array=" << initialState.state_ << std::endl;
      // Test the generation of one realization
      NumericalScalar realization(RandomGenerator::Generate());
      fullprint << "one realization=" << realization << std::endl;
      RandomGeneratorState state(RandomGenerator::GetState());
      fullprint << "new state index=" << state.index_ << std::endl;
      // Test the generation of several realizations
      UnsignedLong size(10000);
      NumericalPoint several(RandomGenerator::Generate(size));
      fullprint << size << " realizations, first=" << several[0] << ", last=" << several[size  - 1] << std::endl;
      // Test the state accessor for writing
      RandomGenerator::SetState(initialState);
      fullprint << "restoring initial state, one realization=" << RandomGenerator::Generate() << std::endl;
      // Test the uniformity of the random generator
      size = 100000;
      NumericalPoint manyPoints(RandomGenerator::Generate(size));
      UnsignedLong slice(10);
      NumericalPoint frequencies(slice, 0.0);
      NumericalScalar mean(0.0);
      for (UnsignedLong i = 0; i < size; i++)
        {
          frequencies[(UnsignedLong)(slice * manyPoints[i])]++;
          mean += manyPoints[i];
        }
      mean /= size;
      fullprint << "mean of " << size << " realizations=" << mean << std::endl;
      for (UnsignedLong i = 0; i < slice; i++)
        {
          frequencies[i] /= size;
          fullprint << "frequency in slice [" << NumericalScalar(i) / slice << ", " << NumericalScalar(i + 1) / slice << "]=" << frequencies[i] << std::endl;
        }
      fullprint << "One integer generation in [[0, " << slice - 1 << "]]=" << RandomGenerator::IntegerGenerate(slice) << std::endl;
      fullprint << "Another integer generation in [[0, " << slice - 1 << "]]=" << RandomGenerator::IntegerGenerate(slice) << std::endl;
      Collection<UnsignedLong> manyUnsignedLong(RandomGenerator::IntegerGenerate(size, slice));
      frequencies = NumericalPoint(slice, 0.0);
      mean = 0.0;
      for (UnsignedLong i = 0; i < size; i++)
        {
          frequencies[manyUnsignedLong[i]]++;
          mean += manyUnsignedLong[i];
        }
      mean /= size;
      fullprint << "mean of " << size << " integer realizations=" << mean << std::endl;
      for (UnsignedLong i = 0; i < slice; i++)
        {
          frequencies[i] /= size;
          fullprint << "frequency for value " << i << "=" << frequencies[i] << std::endl;
        }
    }
  catch (TestFailed & ex)
    {
      std::cerr << ex << std::endl;
      return ExitCode::Error;
    }


  return ExitCode::Success;
}
