random_generators.hpp

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#ifndef RANDOM_GENERATORS
#define RANDOM_GENERATORS

#include "config.hpp"

namespace NTB
{

    std::vector<float> rand_uniform(const double low,
                                    const double high,
                                    const int size,
                                    const int seed = -1)
    {
        assert(low < high);
        assert(size > 0);

        std::vector<float> numbers(size);

        if (seed >= 0)
        {
            std::default_random_engine generator(seed);
            std::uniform_real_distribution<float> uniform(low, high);
            for (int i = 0; i < size; ++i)
                numbers[i] = uniform(generator);
        }
        else
        {
            std::random_device rd;        //Will be used to obtain a seed for the random number engine
            std::mt19937 generator(rd()); //Standard mersenne_twister_engine seeded with rd()
            std::uniform_real_distribution<float> uniform(low, high);

            for (int i = 0; i < size; ++i)
                numbers[i] = uniform(generator);
        }

        return numbers;
    }

    //-------------------------------------------------------------------------
    std::vector<int> randint(const int low,
                             const int high,
                             const int size,
                             const int seed = -1)
    {
        assert(low < high);
        assert(size > 0);

        std::vector<int> numbers(size);

        if (seed >= 0)
        {
            std::default_random_engine generator(seed);
            std::uniform_int_distribution<int> uniform(low, high);
            for (int i = 0; i < size; ++i)
                numbers[i] = uniform(generator);
        }
        else
        {
            std::random_device rd;        //Will be used to obtain a seed for the random number engine
            std::mt19937 generator(rd()); //Standard mersenne_twister_engine seeded with rd()
            std::uniform_int_distribution<int> uniform(low, high);

            for (int i = 0; i < size; ++i)
                numbers[i] = uniform(generator);
        }

        return numbers;
    }

    //-------------------------------------------------------------------------
} // namespace NTB

#endif // !RANDOM_GENERATORS