her2 (USM Version)¶
Computes a rank-2 update of a Hermitian matrix.
Syntax
event her2(queue &exec_queue,
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 vector_class<event> &dependencies = {})
The USM version of her2
supports the following precisions and devices.
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Description
The her2
routines compute two scalar-vector-vector products and adds them to a Hermitian matrix. The operation is defined as
A <- alpha*x*yH + conjg(alpha)*y*xH + A
where:
alpha
is a scalar,
A
is an n
-by-n
Hermitian matrix.
x
and y
are vectors or length n
.
Input Parameters
- exec_queue
The queue where the routine should be executed.
- upper_lower
Specifies whether A is upper or lower triangular. See Data Types for more details.
- n
Number of columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- x
Pointer to input vector
x
. The array holding input vectorx
must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- 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 Storage for more details.- incy
Stride of vector
y
.- a
Pointer to input matrix
A
. The array holding input matrixA
must have size 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 the updated upper triangular part of theHermitian matrix
A
ifupper_lower = upper
, or the updated lowertriangular part of the Hermitian matrixA
ifupper_lower = lower
.The imaginary parts of the diagonal elementsare set to zero.
Return Values
Output event to wait on to ensure computation is complete.