.. _onemkl_blas_scal:

scal
====

Computes the product of a vector by a scalar.

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

The ``scal`` routines computes a scalar-vector product. The operation is defined as: 

.. math::

      x \leftarrow alpha*x

where:

- ``x`` is a vector of ``n`` elements

- ``alpha`` is a scalar

``scal`` supports the following precisions:

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

   * -  T
     -  T_scalar
   * -  ``float``
     -  ``float``
   * -  ``double``
     -  ``double``
   * -  ``std::complex<float>``
     -  ``std::complex<float>``
   * -  ``std::complex<double>``
     -  ``std::complex<double>``
   * -  ``std::complex<float>``
     -  ``float``
   * -  ``std::complex<double>``
     -  ``double``


scal (Buffer Version)
*********************

Syntax
------

.. code-block:: cpp

   namespace oneapi::mkl::blas::column_major {
       void scal(sycl::queue &queue,
                 std::int64_t n,
                 T_scalar alpha,
                 sycl::buffer<T,1> &x,
                 std::int64_t incx)
   }

.. code-block:: cpp

   namespace oneapi::mkl::blas::row_major {
       void scal(sycl::queue &queue,
                 std::int64_t n,
                 T_scalar alpha,
                 sycl::buffer<T,1> &x,
                 std::int64_t incx)
   }

Input Parameters
----------------

queue
   The queue where the routine should be executed.

n
   Number of elements in vector ``x``.

alpha
   Specifies the scalar ``alpha``.

x
   Buffer holding input vector ``x``. Size of the buffer must be at
   least (1 + (``n`` - 1)*abs(``incx``)). See ref:`matrix-storage` for more details.

incx
   Stride of vector ``x``.

Output Parameters
-----------------

x
   Buffer holding updated buffer ``x``.


scal (USM Version)
*********************

Syntax
------

.. code-block:: cpp

   namespace oneapi::mkl::blas::column_major {
       sycl::event scal(sycl::queue &queue,
                        std::int64_t n,
                        T_scalar alpha,
                        T *x,
                        std::int64_t incx,
                        const std::vector<sycl::event> &dependencies = {})
   }

.. code-block:: cpp

   namespace oneapi::mkl::blas::row_major {
       sycl::event scal(sycl::queue &queue,
                        std::int64_t n,
                        T_scalar alpha,
                        T *x,
                        std::int64_t incx,
                        const std::vector<sycl::event> &dependencies = {})
   }

Input Parameters
----------------

queue
   The queue where the routine should be executed.

n
   Number of elements in vector ``x``.

alpha
   Specifies the scalar ``alpha``.

x
   Pointer to the input vector ``x``. Size of the array must be at
   least (1 + (``n`` - 1)\*abs(``incx``)). See ref:`matrix-storage` for more details.

incx
   Stride of vector ``x``.

Output Parameters
-----------------

x
   Pointer to updated array ``x``.

Return Values
-------------

Output event to wait on to ensure computation is complete.