# asum#

Computes the sum of magnitudes of the vector elements.

Description

The asum routine computes the sum of the magnitudes of elements of a real vector, or the sum of magnitudes of the real and imaginary parts of elements of a complex vector:

$result = \sum_{i=1}^{n}(|Re(x_i)| + |Im(x_i)|)$

where x is a vector with n elements.

asum supports the following precisions for data:

T

T_res

float

float

double

double

std::complex<float>

float

std::complex<double>

double

## asum (Buffer Version)#

Syntax

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

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


Input Parameters

queue

The queue where the routine should be executed.

n

Number of elements in vector x.

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.

Output Parameters

result

Buffer where the scalar result is stored (the sum of magnitudes of the real and imaginary parts of all elements of the vector).

Throws

This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.

oneapi::mkl::invalid_argument

oneapi::mkl::unsupported_device

oneapi::mkl::unimplemented

## asum (USM Version)#

Syntax

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

namespace oneapi::mkl::blas::row_major {
sycl::event asum(sycl::queue &queue,
std::int64_t n,
const T *x,
std::int64_t incx,
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 vector x.

x

Pointer to 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.

dependencies

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

Output Parameters

result

Pointer to the output matrix where the scalar result is stored (the sum of magnitudes of the real and imaginary parts of all elements of the vector).

Return Values

Output event to wait on to ensure computation is complete.

Throws

This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.

oneapi::mkl::invalid_argument

oneapi::mkl::unsupported_device