her

oneMKL - Data Parallel C++ Developer Reference

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ID 772045

Date 10/31/2024

Version

Public

Visible to Intel only — GUID: GUID-914FA919-7BF1-4794-A27F-91D54366797C

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her

Computes a rank-1 update of a hermitian matrix.

Description

The her routines compute a scalar-vector-vector product and add the result to a hermitian matrix. The operation is defined as:

where:

alpha is scalar
A is n x n hermitian matrix
x is a vector of length n

her supports the following precisions:

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

her (Buffer Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    void her(sycl::queue &queue,
             oneapi::mkl::uplo upper_lower,
             std::int64_t n,
             Treal alpha,
             sycl::buffer<T,1> &x,
             std::int64_t incx,
             sycl::buffer<T,1> &a,
             std::int64_t lda)
}

namespace oneapi::mkl::blas::row_major {
    void her(sycl::queue &queue,
             oneapi::mkl::uplo upper_lower,
             std::int64_t n,
             Treal alpha,
             sycl::buffer<T,1> &x,
             std::int64_t incx,
             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 rows and 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.
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.

her (USM Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    sycl::event her(sycl::queue &queue,
                    oneapi::mkl::uplo upper_lower,
                    std::int64_t n,
                    oneapi::mkl::value_or_pointer<Treal> alpha,
                    const T *x,
                    std::int64_t incx,
                    T *a,
                    std::int64_t lda,
                    const std::vector<sycl::event> &dependencies = {})
}

namespace oneapi::mkl::blas::row_major {
    sycl::event her(sycl::queue &queue,
                    oneapi::mkl::uplo upper_lower,
                    std::int64_t n,
                    oneapi::mkl::value_or_pointer<Treal> alpha,
                    const T *x,
                    std::int64_t incx,
                    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 rows and 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.
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.

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oneMKL - Data Parallel C++ Developer Reference

her

Description

her (Buffer Version)

her (USM Version)