.. SPDX-FileCopyrightText: 2019-2020 Intel Corporation
..
.. SPDX-License-Identifier: CC-BY-4.0

.. _onemath_lapack_ormrq_scratchpad_size:

ormrq_scratchpad_size
=====================

Computes size of scratchpad memory required for :ref:`onemath_lapack_ormrq` function.

.. container:: section

  .. rubric:: Description
         
``ormrq_scratchpad_size`` supports the following precisions.

     .. list-table:: 
        :header-rows: 1
  
        * -  T 
        * -  ``float`` 
        * -  ``double`` 

Computes the number of elements of type ``T`` the scratchpad memory to be passed to :ref:`onemath_lapack_ormrq` function should be able to hold.
Calls to this routine must specify the template parameter explicitly.

ormrq_scratchpad_size
---------------------

.. container:: section

  .. rubric:: Syntax

.. code-block:: cpp

    namespace oneapi::math::lapack {
      template <typename T>
      std::int64_t ormrq_scratchpad_size(cl::sycl::queue &queue, oneapi::math::side side, oneapi::math::transpose trans, std::int64_t m, std::int64_t n, std::int64_t k, std::int64_t lda, std::int64_t ldc);
    }

.. container:: section

  .. rubric:: Input Parameters
         
queue
   Device queue where calculations by the ormrq function will be performed.

side
   If ``side = oneapi::math::side::left``, :math:`Q` or :math:`Q^T` is applied to :math:`C` from the left. 
   
   If ``side = oneapi::math::side::right``, :math:`Q` or :math:`Q^T` is applied to :math:`C` from the right.

trans
   If ``trans=oneapi::math::transpose::nontrans``, the routine multiplies :math:`C` by :math:`Q`.

   If ``trans=oneapi::math::transpose::trans``, the routine multiplies :math:`C` by :math:`Q^T`.

m
   The number of rows in the matrix :math:`C` (:math:`0 \le m`).

n
   The number of columns in the matrix :math:`C` (:math:`0 \le n \le m`).

k
   The number of elementary reflectors whose product defines the matrix :math:`Q` (:math:`0 \le k \le n`).

lda
   The leading dimension of ``a``.

ldc
   The leading dimension of ``c``.

.. container:: section

  .. rubric:: Throws
         
This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.

:ref:`oneapi::math::unimplemented<onemath_exception_unimplemented>`

:ref:`oneapi::math::unsupported_device<onemath_exception_unsupported_device>`

:ref:`oneapi::math::lapack::invalid_argument<onemath_lapack_exception_invalid_argument>`

   Exception is thrown in case of incorrect supplied argument value.
   Position of wrong argument can be determined by `info()` method of exception object.

.. container:: section

  .. rubric:: Return Value

The number of elements of type ``T`` the scratchpad memory to be passed to :ref:`onemath_lapack_ormrq` function should be able to hold.

**Parent topic:** :ref:`onemath_lapack-linear-equation-routines`