rotm

Performs modified Givens rotation of points in the plane.

Syntax

void rotm(queue &exec_queue, std::int64_t n, buffer<T, 1> &x, std::int64_t incx, buffer<T, 1> &y, std::int64_t incy, buffer<T, 1> &param)

rotm supports the following precisions and devices.

T

Devices Supported

float

Host, CPU, and GPU

double

Host, CPU, and GPU

Description

Given two vectors x and y, each vector element of these vectors is replaced as follows:


image0

for i from 1 to n, where H is a modified Givens transformation matrix.

Input Parameters

exec_queue

The queue where the routine should be executed.

n

Number of elements in vector x.

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.

y

Buffer holding input vector x. The buffer must be of size at least (1 + (n - 1)*abs(incy)). See Matrix and Vector Storage for more details.

incy

Stride of vector y.

param

Buffer holding an array of size 5. The elements of the param array are:

param[0] contains a switch, flag,

param[1-4] contain h11,h21, h12,h22 respectively, the components ofthe modified Givens transformation matrix H.

Depending on the values of flag, thecomponents of H are set as follows:

flag = -1.0:
image1
flag = 0.0:
image2
flag = 1.0:
image3
flag = -2.0:
image4

In the last three cases, the matrix entries of 1.0, -1.0, 0.0 are assumed based on the value of flag and are not required to be set in the param vector.

Output Parameters

x

Buffer holding updated buffer x.

y

Buffer holding updated buffer y.