random.h

// Random numbers generation
// Written by Sergey G. Kosov in 2013 for Project X
// Simplified (C++11) by Sergey G. Kosov in 2016 for Project X
#pragma once

#include "types.h"
#include <random>

namespace DirectGraphicalModels
{
    // ================================ Random Namespace ==============================
    namespace random {
        template <typename T>
        inline T u(T min, T max)
        {
            static thread_local std::mt19937 generator(static_cast<unsigned int>(clock() + std::hash<std::thread::id>()(std::this_thread::get_id())));
            std::uniform_int_distribution<T> distribution(min, max);
            return distribution(generator);
        }
        template <typename T>
        inline T U(T min = 0, T max = 1)
        {
            static thread_local std::mt19937 generator(static_cast<unsigned int>(clock() + std::hash<std::thread::id>()(std::this_thread::get_id())));
            std::uniform_real_distribution<T> distribution(min, max);
            return distribution(generator);
        }
        template <typename T>
        inline T N(T mu = 0, T sigma = 1)
        {
            static thread_local std::mt19937 generator(static_cast<unsigned int>(clock() + std::hash<std::thread::id>()(std::this_thread::get_id())));
            std::normal_distribution<T> distribution(mu, sigma);
            return distribution(generator);
        }


        inline Mat U(cv::Size size, int type, double min = 0, double max = 1)
        {
            static thread_local RNG rng(static_cast<unsigned int>(clock() + std::hash<std::thread::id>()(std::this_thread::get_id())));
            Mat res(size, type);
            rng.fill(res, RNG::UNIFORM, min, max);
            return res;
        }
        inline Mat N(cv::Size size, int type, double mu = 0, double sigma = 1)
        {
            static thread_local RNG rng(static_cast<unsigned int>(clock() + std::hash<std::thread::id>()(std::this_thread::get_id())));
            Mat res(size, type);
            rng.fill(res, RNG::NORMAL, mu, sigma);
            return res;
        }

    }
}