syr¶
Computes a rank-1 update of a symmetric matrix.
Syntax
-
void
syr
(queue &exec_queue, uplo upper_lower, std::int64_t n, T alpha, buffer<T, 1> &x, std::int64_t incx, 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 |
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
A <- alpha*x*xT + A
where:
alpha
is scalar,
A
is an n
-by-n
symmetric matrix,
x
is a vector of length n
.
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
.