hpr¶
Computes a rank-1 update of a Hermitian packed matrix.
Syntax
void hpr(queue &exec_queue, uplo upper_lower, std::int64_t n, T alpha, buffer<T,1> &x, std::int64_t incx, buffer<T,1> &a)
hpr
supports the following precisions and devices.
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Description
The hpr routines compute a scalar-vector-vector product and add the result to a Hermitian packed matrix. The operation is defined as
A <- alpha*x*xH + A
where:
alpha
is scalar,
A
is an n
-by-n
Hermitian matrix, supplied in packed form,
x
is a vector of 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 rows and columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- 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
.- a
Buffer holding input matrix
A
. Must have size at least (n
*(n
-1))/2. See Matrix and Vector Storage for more details.The imaginary part of the diagonal elements need not be set and are assumed to be zero
Output Parameters
- a
Buffer holding the updated upper triangularpart of the Hermitian matrix
A
ifupper_lower =upper
, or the updated lower triangular part of theHermitian matrixA
ifupper_lower =lower
.The imaginary parts of the diagonal elements are set tozero.