cblas_?rotm

Performs modified Givens rotation of points in the plane.

Syntax

void

cblas_srotm

(

const

MKL_INT

float

const

MKL_INT

incx

float

const

MKL_INT

incy

const

float

*param

);

void

cblas_drotm

(

const

MKL_INT

double

const

MKL_INT

incx

double

const

MKL_INT

incy

const

double

*param

);

Include Files

mkl.h

Description

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

for i=1 to n, where H is a modified Givens transformation matrix whose values are stored in the

param[1]

through

param[4]

array. See discussion on the param argument.

Input Parameters

n: Specifies the number of elements in vectors x and y.
x: Array, size at least
(1 + (n -1)*abs(incx))
.
incx: Specifies the increment for the elements of x.
y: Array, size at least
(1 + (n -1)*abs(incy))
.
incy: Specifies the increment for the elements of y.
param: Array, size 5.
The elements of the param array are:
param[0]
contains a switch, flag.
param[1-4]
contain h₁₁, h₂₁, h₁₂, and h₂₂, respectively, the components of the array H.
Depending on the values of flag, the components of H are set as follows:
flag =
-1.0
:

flag =
0.0
:

flag =
1.0
:

flag =
-2.0
:

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