her2¶
Computes a rank-2 update of a hermitian matrix.
Description¶
The her2
routines compute two scalar-vector-vector products and add them to a hermitian matrix. The operation is defined as:
where:
alpha
is a scalarA
isn
xn
hermitian matrixx
andy
are vectors or lengthn
her2
supports the following precisions:
T |
---|
|
|
her2 (Buffer Version)¶
Syntax¶
namespace oneapi::mkl::blas::column_major {
void her2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<T,1> &y,
std::int64_t incy,
sycl::buffer<T,1> &a,
std::int64_t lda)
}
namespace oneapi::mkl::blas::row_major {
void her2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<T,1> &y,
std::int64_t incy,
sycl::buffer<T,1> &a,
std::int64_t lda)
}
Input Parameters¶
- queue
The queue where the routine should be executed.
- upper_lower
Specifies whether matrix
A
is upper or lower triangular. See Data Types for more details.- n
Number of columns of matrix
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- x
Buffer holding input vector
x
. Size of the buffer must be at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
. Must not be zero.- y
Buffer holding input/output vector
y
. Size of the buffer must be at least (1 + (n
- 1)*abs(incy
)). See Matrix Storage for more details.- incy
Stride of vector
y
. Must not be zero.- a
Buffer holding input matrix
A
. Size of the buffer must be at leastlda
*n
. See Matrix Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastn
and positive.
Output Parameters¶
- a
Buffer holding updated upper triangular part of the hermitian matrix
A
ifupper_lower=upper
, or updated lower triangular part of the hermitian matrixA
ifupper_lower=lower
.If
alpha
is zero,A
matrix is unchanged, otherwise imaginary parts of the diagonal elements are set to zero.
her2 (USM Version)¶
Syntax¶
namespace oneapi::mkl::blas::column_major {
sycl::event her2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
const T *x,
std::int64_t incx,
const T *y,
std::int64_t incy,
T *a,
std::int64_t lda,
const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
sycl::event her2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
const T *x,
std::int64_t incx,
const T *y,
std::int64_t incy,
T *a,
std::int64_t lda,
const std::vector<sycl::event> &dependencies = {})
}
Input Parameters¶
- queue
The queue where the routine should be executed.
- upper_lower
Specifies whether matrix
A
is upper or lower triangular. See Data Types for more details.- n
Number of columns of matrix
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- x
Pointer to input vector
x
. Size of the array holding input vectorx
must be at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
. Must not be zero.- y
Pointer to input/output vector
y
. Size of the array holding input/output vectory
must be at least (1 + (n
- 1)*abs(incy
)). See Matrix Storage for more details.- incy
Stride of vector
y
. Must not be zero.- a
Pointer to input matrix
A
. Size of the array holding input matrixA
must be at leastlda
*n
. See Matrix Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastn
and positive.- dependencies
List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
Output Parameters¶
- a
Pointer to updated upper triangular part of the hermitian matrix
A
ifupper_lower=upper
, or updated lower triangular part of the hermitian matrixA
ifupper_lower=lower
.If
alpha
is zero,A
matrix is unchanged, otherwise imaginary parts of the diagonal elements are set to zero.
Return Values¶
Output event to wait on to ensure computation is complete.