syr#
Computes a rank-1 update of a symmetric matrix.
Description
The syr
routines compute a scalar-vector-vector product add them and
add the result to a matrix, with a symmetric matrix. The operation is
defined as:
where:
alpha
is scalar,
A
is an n
-by-n
symmetric matrix,
x
is a vector of length n
.
syr
supports the following precisions.
T
float
double
syr (Buffer Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
void syr(sycl::queue &queue,
onemkl::uplo upper_lower,
std::int64_t n,
T 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 syr(sycl::queue &queue,
onemkl::uplo upper_lower,
std::int64_t n,
T 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
A
is upper or lower triangular. See oneMKL Defined Datatypes for more details.- 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 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- a
Buffer holding input matrix
A
. Must have size at leastlda
*n
. See Matrix Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastn
, and positive.
Output Parameters
- a
Buffer holding the updated upper triangular part of the symmetric matrix
A
ifupper_lower
=upper
or the updated lower triangular part of the symmetric matrixA
ifupper_lower
=lower
.
syr (USM Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
sycl::event syr(sycl::queue &queue,
onemkl::uplo upper_lower,
std::int64_t n,
T 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 syr(sycl::queue &queue,
onemkl::uplo upper_lower,
std::int64_t n,
T 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
A
is upper or lower triangular. See oneMKL Defined Datatypes for more details.- 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 vectorx
must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- a
Pointer to input matrix
A
. The array holding input matrixA
must have size at leastlda
*n
. See Matrix Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastn
, 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 the updated upper triangular part of the symmetric matrix
A
ifupper_lower
=upper
or the updated lower triangular part of the symmetric matrixA
ifupper_lower
=lower
.
Return Values
Output event to wait on to ensure computation is complete.
Parent topic: BLAS Level 2 Routines