Computes a rank-2 update of a symmetric packed matrix.
void spr2(queue &exec_queue, uplo upper_lower, std::int64_t n, T alpha, buffer<T,1> &x, std::int64_t incx, buffer<T,1> &y, std::int64_t incy, buffer<T,1> &a);
spr2 supports the following precisions and devices.
T | Devices Supported |
---|---|
float | Host, CPU, and GPU |
double | Host, CPU, and GPU |
The spr2 routines compute two scalar-vector-vector products and add them to a symmetric packed matrix. The operation is defined as
A <- alpha*x*yT + alpha*y*xT + A
where:
alpha is scalar,
A is an n-by-n symmetric matrix, supplied in packed form,
x and y are vectors of length n.
The queue where the routine should be executed.
Specifies whether A is upper or lower triangular. See Data Types for more details.
Number of rows and columns of A. Must be at least zero.
Scaling factor for the matrix-vector product.
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.
Stride of vector x.
Buffer holding input/output vector y. The buffer must be of size at least (1 + (n - 1)*abs(incy)). See Matrix and Vector Storage for more details.
Stride of vector y.
Buffer holding input matrix A. Must have size at least (n*(n-1))/2. See Matrix and Vector Storage for more details.
Buffer holding the updated upper triangular part of the symmetric matrix A if upper_lower = upper or the updated lower triangular part of the symmetric matrix A if upper_lower = lower.