spr¶
Performs a rank-1 update of a symmetric packed matrix.
Syntax
-
void
spr(queue &exec_queue, uplo upper_lower, std::std::int64_t n, T alpha, buffer<T, 1> &x, std::int64_t incx, buffer<T, 1> &a)¶
spr supports the following precisions and devices.
T |
Devices Supported |
|---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Description
The spr routines compute a scalar-vector-vector product and add the result to a symmetric packed matrix. The operation is defined as
A <- alpha*x*xT + A
where:
alpha is scalar,
A is an n-by-n symmetric matrix, supplied in packed form,
x is a vector of length n.
Input Parameters
- exec_queue
The queue where the routine should be executed.
- upper_lower
Specifies whether
Ais upper or lower triangular. See Data Types for more details.- n
Number of rows and 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 least (n*(n-n))/2. See Matrix and Vector Storage for more details.
Output Parameters
sycl:
- a
Buffer holding the updated upper triangularpart of the symmetric matrix
Aifupper_lower =upper, or the updated lower triangular part of thesymmetric matrixAifupper_lower =lower.