hemv¶
Computes a matrix-vector product using a Hermitian matrix.
hemv
supports the following precisions.
T
std::complex<float>
std::complex<double>
Description
The hemv
routines compute a scalar-matrix-vector product and add the
result to a scalar-vector product, with a Hermitian matrix. The
operation is defined as
y <- alpha*A*x + beta*y
where:
alpha
and beta
are scalars,
A
is an n
-by-n
Hermitian matrix,
x
and y
are vectors of length n
.
hemv (Buffer Version)¶
Syntax
-
void
onemkl::blas
::
hemv
(sycl::queue &queue, onemkl::uplo upper_lower, std::int64_t n, T alpha, sycl::buffer<T, 1> &a, std::int64_t lda, sycl::buffer<T, 1> &x, std::int64_t incx, T beta, sycl::buffer<T, 1> &y, std::int64_t incy)¶
Input Parameters
- queue
The queue where the routine should be executed.
- upper_lower
Specifies whether A is upper or lower triangular. See oneMKL defined datatypes for more details.
- n
Number of rows and columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- a
Buffer holding input matrix
A
. Must have size at leastlda
*n
. See Matrix and Vector Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastm
, and positive.- x
Buffer holding input vector
x
. The buffer must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix and Vector Storage for more details.- incx
Stride of vector
x
.- beta
Scaling factor for vector
y
.- y
Buffer holding input/output vector
y
. The buffer must be of size at least (1 + (n
- 1)*abs(incy
)). See Matrix and Vector Storage for more details.- incy
Stride of vector
y
.
Output Parameters
- y
Buffer holding the updated vector
y
.
hemv (USM Version)¶
Syntax
-
sycl::event
onemkl::blas
::
hemv
(sycl::queue &queue, onemkl::uplo upper_lower, std::int64_t n, T alpha, const T *a, std::int64_t lda, const T *x, std::int64_t incx, T beta, T *y, std::int64_t incy, const sycl::vector_class<sycl::event> &dependencies = {})¶
Input Parameters
- queue
The queue where the routine should be executed.
- upper_lower
Specifies whether A is upper or lower triangular. See oneMKL defined datatypes for more details.
- n
Number of rows and columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- a
Pointer to input matrix
A
. The array holding input matrixA
must have size at leastlda
*n
. See Matrix and Vector Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastm
, and positive.- x
Pointer to input vector
x
. The array holding input vectorx
must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix and Vector Storage for more details.- incx
Stride of vector
x
.- beta
Scaling factor for vector
y
.- y
Pointer to input/output vector
y
. The array holding input/output vectory
must be of size at least (1 + (n
- 1)*abs(incy
)). See Matrix and Vector 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.
Output Parameters
- y
Pointer to the updated vector
y
.
Return Values
Output event to wait on to ensure computation is complete.
Parent topic: BLAS Level 2 Routines