.. SPDX-FileCopyrightText: 2019-2020 Intel Corporation .. .. SPDX-License-Identifier: CC-BY-4.0 .. _onemath_rng_mrg32k3a: mrg32k3a ======== The combined multiple recursive pseudorandom number generator MRG32k3a. .. _onemath_rng_mrg32k3a_description: .. rubric:: Description MRG32k3a engine is a 32-bit combined multiple recursive generator with two components of order 3 :ref:`[L'Ecuyer99a] `. MRG32k3a combined generator meets the requirements for modern RNGs, such as good multidimensional uniformity, or a long period (:math:`p \approx 2^{191}`). .. container:: section .. rubric:: Generation algorithm :math:`x_n=a_{11} x_{n-1} + a_{12} x_{n-2} + a_{13} x_{n-3}(mod \ m_{1})` :math:`y_n = a_{21} y_{n-1} + a_{22} y_{n-2} + a_{23} (mod \ m_2)` :math:`z_n = x_n - y_n (mod \ m_{1})` :math:`u_n = z_n / m_1` :math:`a_{11} = 0, a_{12} = 1403580, a_{13} = -810728, m_1 = 2^{32} - 209` :math:`a_{21} = 527612, a_{22} = 0, a_{23} = -1370589, m_2 = 2^{32} - 22853` .. _onemath_rng_mrg32k3a_description_syntax: class mrg32k3a -------------- .. rubric:: Syntax .. code-block:: cpp namespace oneapi::math::rng { class mrg32k3a { public: static constexpr std::uint32_t default_seed = 1; mrg32k3a(sycl::queue queue, std::uint32_t seed = default_seed); mrg32k3a(sycl::queue queue, std::initializer_list seed); mrg32k3a(const mrg32k3a& other); mrg32k3a(mrg32k3a&& other); mrg32k3a& operator=(const mrg32k3a& other); mrg32k3a& operator=(mrg32k3a&& other); ~mrg32k3a(); }; } .. container:: section .. rubric:: Class Members .. list-table:: :header-rows: 1 * - Routine - Description * - `mrg32k3a(sycl::queue queue, std::uint32_t seed = default_seed)`_ - Constructor for common seed initialization of the engine * - `mrg32k3a(sycl::queue queue, std::initializer_list seed)`_ - Constructor for extended seed initialization of the engine * - `mrg32k3a(const mrg32k3a& other)`_ - Copy constructor * - `mrg32k3a(mrg32k3a&& other)`_ - Move constructor * - `mrg32k3a& operator=(const mrg32k3a& other)`_ - Copy assignment operator * - `mrg32k3a& operator=(mrg32k3a&& other)`_ - Move assignment operator .. container:: section .. rubric:: Constructors .. _`mrg32k3a(sycl::queue queue, std::uint32_t seed = default_seed)`: .. code-block:: cpp mrg32k3a::mrg32k3a(sycl::queue queue, std::uint32_t seed = default_seed) .. container:: section .. rubric:: Input Parameters queue Valid ``sycl::queue object``, calls of the :ref:`oneapi::math::rng::generate()` routine submits kernels in this queue to obtain random numbers from a given engine. seed The initial conditions of the generator state, assume :math:`x_{-3} = seed \ mod \ m_1, x_{-2} = x_{-1} = y_{-3} = y_{-2} = y_{-1} = 1`. .. _`mrg32k3a(sycl::queue queue, std::initializer_list seed)`: .. code-block:: cpp mrg32k3a::mrg32k3a(sycl::queue queue, std::initializer_list seed) .. container:: section .. rubric:: Input Parameters queue Valid ``sycl::queue`` object, calls of the :ref:`oneapi::math::rng::generate()` routine submits kernels in this queue to obtain random numbers from a given engine. seed The initial conditions of the generator state, assume if :math:`n = 0: x_{-3} = x_{-2} = x_{-1} = y_{-3} = y_{-2} = y_{-1} = 1` if :math:`n = 1: x_{-3} = seed[0] \ mod \ m_1, x_{-2} = x_{-1} = y_{-3} = y_{-2} = y_{-1} = 1` if :math:`n = 2: x_{-3} = seed[0] \ mod \ m_1, x_{-2} = seed[1] \ mod \ m_1, x_{-1} = y_{-3} = y_{-2} = y_{-1} = 1` if :math:`n = 3: x_{-3} = seed[0] \ mod \ m_1, x_{-2} = seed[1] \ mod \ m_1, x_{-1} = seed[2] \ mod \ m_1` :math:`y_{-3} = y_{-2} = y_{-1} = 1` if :math:`n = 4: x_{-3} = seed[0] \ mod \ m_1, x_{-2} = seed[1] \ mod \ m_1, x_{-1} = seed[2] \ mod \ m_1` :math:`y_{-3} = seed[3] \ mod \ m_2, y_{-2} = y_{-1} = 1` if :math:`n = 5: x_{-3} = seed[0] \ mod \ m_1, x_{-2} = seed[1] \ mod \ m_1, x_{-1} = seed[2] \ mod \ m_1` :math:`y_{-3} = seed[3] \ mod \ m_2, y_{-2} = seed[4] \ mod \ m_2, y_{-1} = 1` if :math:`n \geqslant 6: x_{-3} = seed[0] \ mod \ m_1, x_{-2} = seed[1] \ mod \ m_1, x_{-1} = seed[2] \ mod \ m_1` :math:`y_{-3} = seed[3] \ mod \ m_2, y_{-2} = seed[4] \ mod \ m_2, y_{-1} = seed[5] \ mod \ m_2` if the values prove to be :math:`x_{-3} = x_{-2} = x_{-1} = 0`, assume :math:`x_{-3} = 1` if the values prove to be :math:`y_{-3} = y_{-2} = y_{-1} = 0`, assume :math:`y_{-3} = 1` .. _`mrg32k3a(const mrg32k3a& other)`: .. code-block:: cpp mrg32k3a::mrg32k3a(const mrg32k3a& other) .. container:: section .. rubric:: Input Parameters other Valid ``mrg32k3a`` object. The ``queue`` and state of the other engine is copied and applied to the current engine. .. _`mrg32k3a(mrg32k3a&& other)`: .. code-block:: cpp mrg32k3a::mrg32k3a(mrg32k3a&& other) .. container:: section .. rubric:: Input Parameters other Valid ``mrg32k3a`` object. The ``queue`` and state of the other engine is moved to the current engine. .. _`mrg32k3a& operator=(const mrg32k3a& other)`: .. code-block:: cpp mrg32k3a::mrg32k3a& operator=(const mrg32k3a& other) .. container:: section .. rubric:: Input Parameters other Valid ``mrg32k3a`` object. The ``queue`` and state of the other engine is copied and applied to the current engine. .. _`mrg32k3a& operator=(mrg32k3a&& other)`: .. code-block:: cpp mrg32k3a::mrg32k3a& operator=(mrg32k3a&& other) .. container:: section .. rubric:: Input Parameters other Valid ``mrg32k3a`` r-value object. The ``queue`` and state of the other engine is moved to the current engine. **Parent topic:** :ref:`onemath_rng_engines_basic_random_number_generators`