# ger¶

Computes a rank-1 update of a general matrix.

Description

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

$A \leftarrow alpha*x*y^T + A$

where:

alpha is scalar,

A is an m-by-n matrix,

x is a vector of length m,

y is a vector of length n.

ger supports the following precisions.

T

float

double

## ger (Buffer Version)¶

Syntax

namespace oneapi::mkl::blas::column_major {
void ger(sycl::queue &queue,
std::int64_t m,
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 ger(sycl::queue &queue,
std::int64_t m,
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.

m

Number of rows of A. Must be at least zero.

n

Number of 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 + (m - 1)*abs(incx)). See Matrix Storage for more details.

incx

Stride of vector x.

y

Buffer holding input/output vector y. The buffer must be of size at least (1 + (n - 1)*abs(incy)). See Matrix Storage for more details.

incy

Stride of vector y.

a

Buffer holding input matrix A. Must have size at least lda*n if column major layout is used or at least lda*m if row major layout is used. See Matrix Storage for more details.

lda

Leading dimension of matrix A. Must be positive and at least m if column major layout is used or at least n if row major layout is used.

Output Parameters

a

Buffer holding the updated matrix A.

## ger (USM Version)¶

Syntax

namespace oneapi::mkl::blas::column_major {
sycl::event ger(sycl::queue &queue,
std::int64_t m,
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 ger(sycl::queue &queue,
std::int64_t m,
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.

m

Number of rows of A. Must be at least zero.

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 vector x must be of size at least (1 + (m - 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 vector y 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. Must have size at least lda*n if column major layout is used or at least lda*m if row major layout is used. See Matrix Storage for more details.

lda

Leading dimension of matrix A. Must be positive and at least m if column major layout is used or at least n if row major layout is used.

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 matrix A.

Return Values

Output event to wait on to ensure computation is complete.

Parent topic: BLAS Level 2 Routines