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 ann
-by-n
symmetric matrix,x
is a vector of lengthn
.
API¶
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)
}
syr
supports the following precisions and devices.
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Input Parameters¶
- exec_queue
The queue where the routine should be executed.
- upper_lower
Specifies whether
A
is upper or lower triangular. See Data Types 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 and Vector Storage for more details.- incx
Stride of vector
x
.- a
Buffer holding input matrix
A
. Must have size at leastlda
*n
. See Matrix and Vector Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastn
, and positive.
Output Parameters¶
- a
Buffer holding the updated upper triangularpart of the symmetric matrix
A
ifupper_lower =upper
or the updated lower triangular part of thesymmetric matrixA
ifupper_lower =lower
.