.. _oneapi-mkl-rng-device-mrg32k3a:

oneapi::mkl::rng::device::mrg32k3a
==================================


.. contents::
    :local:
    :depth: 1

Description
***********

The combined multiple recursive pseudorandom number generator MRG32k3a [:ref:`L'Ecuyer99a<bibliography>`].


API
***


Syntax
------

.. code-block:: cpp

   template<std::int32_t VecSize = 1>
     class mrg32k3a {
     public:
     static constexpr std::uint32_t default_seed = 1;
     static constexpr std::int32_t vec_size = VecSize;
     mrg32k3a() : mrg32k3a(default_seed) {}
     mrg32k3a(std::uint32_t seed, std::uint64_t offset = 0);
     mrg32k3a(std::initializer_list<std::uint32_t> seed, std::uint64_t offset = 0);
     mrg32k3a(std::uint32_t seed, std::initializer_list<std::uint64_t> offset);
     mrg32k3a(std::initializer_list<std::uint32_t> seed, std::initializer_list<std::uint64_t> offset);
   };



Include Files
-------------

- ``oneapi/mkl/rng/device.hpp``


Template Parameters
-------------------

.. list-table::
   :header-rows: 1

   * - Name
     - Type
     - Description
   * - VecSize
     - ``std::int32_t``
     - Describes the size of vector which will be produced by generate function by this engine. VecSize values may be 1, 2, 3, 4,   8, 16 as ``sycl::vec`` class size. By default VecSize = 1, for this case, a single random number is returned by the ``oneapi::mkl::rng::device::generate`` function.




Constructors Input Parameters
-----------------------------


.. list-table::
   :header-rows: 1

   * - Name
     - Type
     - Description

   * - seed
     - ``std::uint32_t``
       ``std::initializer_list<std::uint32_t>``
     - Initial conditions of the engine state.

   * - offset

     - ``std::uint64_t``
       ``std::initializer_list<std::uint64_t>``

     - number of skipped elements, for ``initializer_list``
       offset is calculated as: ``num_to_skip`` [0]+ ``num_to_skip`` [1]*2\ :sup:`64` + ``num_to_skip`` [2]\* 2\ :sup:`128` + … +
       ``num_to_skip`` [``n``-1]\*2\ :sup:`64` \*(``n``-1).




See :ref:`VS Notes<bibliography>` for detailed descriptions.