her2

oneMKL - Data Parallel C++ Developer Reference

Download PDF

ID 772045

Date 11/07/2023

Version

Public

A newer version of this document is available. Customers should click here to go to the newest version.

Visible to Intel only — GUID: GUID-AC579702-5161-454C-AD45-E97F92086CB1

View Details

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 scalar
A is n x n hermitian matrix
x and y are vectors or length n

her2 supports the following precisions:

T
`std::complex<float>`
`std::complex<double>`

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 least lda * n. See Matrix Storage for more details.
lda: Leading dimension of matrix A. Must be at least n and positive.

Output Parameters

a

Buffer holding updated upper triangular part of the hermitian matrix A if upper_lower=upper, or updated lower triangular part of the hermitian matrix A if upper_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,
                     oneapi::mkl::value_or_pointer<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,
                     oneapi::mkl::value_or_pointer<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. See Scalar Arguments for more information on the value_or_pointer data type.
x: Pointer to input vector x. Size of the array holding input vector x 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 vector y 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 matrix A must be at least lda * n. See Matrix Storage for more details.
lda: Leading dimension of matrix A. Must be at least n 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 if upper_lower=upper, or updated lower triangular part of the hermitian matrix A if upper_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.

Select Your Language

Using Intel.com Search

Quick Links

Recent Searches

Advanced Search

Only search in

oneMKL - Data Parallel C++ Developer Reference

her2

Description

her2 (Buffer Version)

her2 (USM Version)