# dot¶

Computes the dot product of two real vectors.

Description

The dot routines perform a dot product between two vectors:

$result = \sum_{i=1}^{n}X_iY_i$

dot supports the following precisions for data.

T

T_res

float

float

double

double

float

double

Note

For the mixed precision version (inputs are float while result is double), the dot product is computed with double precision.

## dot (Buffer Version)¶

Syntax

namespace oneapi::mkl::blas::column_major {
void dot(sycl::queue &queue,
std::int64_t n,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<T,1> &y,
std::int64_t incy,
sycl::buffer<T_res,1> &result)
}

namespace oneapi::mkl::blas::row_major {
void dot(sycl::queue &queue,
std::int64_t n,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<T,1> &y,
std::int64_t incy,
sycl::buffer<T_res,1> &result)
}


Input Parameters

queue

The queue where the routine should be executed.

n

Number of elements in vectors x and y.

x

Buffer holding input vector x. The buffer must be of size at least (1 + (n – 1)*abs(incx)). See Matrix Storage for more details.

incx

Stride of vector x.

y

Buffer holding input 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.

Output Parameters

result

Buffer where the result (a scalar) will be stored.

## dot (USM Version)¶

Syntax

namespace oneapi::mkl::blas::column_major {
sycl::event dot(sycl::queue &queue,
std::int64_t n,
const T *x,
std::int64_t incx,
const T *y,
std::int64_t incy,
T_res *result,
const std::vector<sycl::event> &dependencies = {})
}

namespace oneapi::mkl::blas::row_major {
sycl::event dot(sycl::queue &queue,
std::int64_t n,
const T *x,
std::int64_t incx,
const T *y,
std::int64_t incy,
T_res *result,
const std::vector<sycl::event> &dependencies = {})
}


Input Parameters

queue

The queue where the routine should be executed.

n

Number of elements in vectors x and y.

x

Pointer to the input vector x. The array holding the vector x 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 the input vector y. The array holding the vector y must be of size at least (1 + (n – 1)*abs(incy)). See Matrix Storage for more details.

incy

Stride of vector y.

dependencies

List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.

Output Parameters

result

Pointer to where the result (a scalar) will be stored.

Return Values

Output event to wait on to ensure computation is complete.

Parent topic: BLAS Level 1 Routines