.. _onemkl_blas_axpy: axpy ==== Computes a vector-scalar product and adds the result to a vector. .. _onemkl_blas_axpy_description: .. rubric:: Description The ``axpy`` routines compute a scalar-vector product and add the result to a vector: .. math:: y \leftarrow alpha * x + y where: ``x`` and ``y`` are vectors of ``n`` elements, ``alpha`` is a scalar. ``axpy`` supports the following precisions. .. list-table:: :header-rows: 1 * - T * - ``float`` * - ``double`` * - ``std::complex`` * - ``std::complex`` .. _onemkl_blas_axpy_buffer: axpy (Buffer Version) --------------------- .. rubric:: Syntax .. code-block:: cpp namespace oneapi::mkl::blas::column_major { void axpy(sycl::queue &queue, std::int64_t n, T alpha, sycl::buffer &x, std::int64_t incx, sycl::buffer &y, std::int64_t incy) } .. code-block:: cpp namespace oneapi::mkl::blas::row_major { void axpy(sycl::queue &queue, std::int64_t n, T alpha, sycl::buffer &x, std::int64_t incx, sycl::buffer &y, std::int64_t incy) } .. container:: section .. rubric:: 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``. The buffer must be of size at least (1 + (``n`` – 1)*abs(``incx``)). See :ref:`matrix-storage` for more details. incx Stride of vector ``x``. y Buffer holding input vector ``y``. The buffer must be of size at least (1 + (``n`` – 1)*abs(``incy``)). See :ref:`matrix-storage` for more details. incy Stride of vector ``y``. .. container:: section .. rubric:: Output Parameters y Buffer holding the updated vector ``y``. .. _onemkl_blas_axpy_usm: axpy (USM Version) ------------------ .. rubric:: Syntax .. code-block:: cpp namespace oneapi::mkl::blas::column_major { sycl::event axpy(sycl::queue &queue, std::int64_t n, T alpha, const T *x, std::int64_t incx, T *y, std::int64_t incy, const std::vector &dependencies = {}) } .. code-block:: cpp namespace oneapi::mkl::blas::row_major { sycl::event axpy(sycl::queue &queue, std::int64_t n, T alpha, const T *x, std::int64_t incx, T *y, std::int64_t incy, const std::vector &dependencies = {}) } .. container:: section .. rubric:: 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``. The array holding the vector ``x`` must be of size at least (1 + (``n`` – 1)*abs(``incx``)). See :ref:`matrix-storage` for more details. incx Stride of vector ``x``. y Pointer to the input vector ``y``. The array holding the vector ``y`` must be of size at least (1 + (``n`` – 1)*abs(``incy``)). See :ref:`matrix-storage` for more details. incy Stride of vector ``y``. dependencies List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies. .. container:: section .. rubric:: Output Parameters y Pointer to the updated vector ``y``. .. container:: section .. rubric:: Return Values Output event to wait on to ensure computation is complete. **Parent topic:** :ref:`blas-level-1-routines`