stdlib_drotm Subroutine

public pure subroutine stdlib_drotm(n, dx, incx, dy, incy, dparam)

DROTM applies the modified Givens transformation, $H$, to the 2-by-N matrix $$\left[ \begin{array}{c}DX^T\\DY^T\\ \end{array} \right],$$ where $^T$ indicates transpose. The elements of $DX$ are in DX(LX+IINCX), I = 0:N-1, where LX = 1 if INCX >= 0, else LX = (-INCX)N, and similarly for DY using LY and INCY. With DPARAM(1)=DFLAG, $H$ has one of the following forms: $$H=\underbrace{\begin{bmatrix}DH_{11} & DH_{12}\\DH_{21} & DH_{22}\end{bmatrix}}_{DFLAG=-1}, \underbrace{\begin{bmatrix}1 & DH_{12}\\DH_{21} & 1\end{bmatrix}}_{DFLAG=0}, \underbrace{\begin{bmatrix}DH_{11} & 1\\-1 & DH_{22}\end{bmatrix}}_{DFLAG=1}, \underbrace{\begin{bmatrix}1 & 0\\0 & 1\end{bmatrix}}_{DFLAG=-2}.$$
See DROTMG for a description of data storage in DPARAM.

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=ilp),	intent(in)			::	n
real(kind=dp),	intent(inout)			::	dx(*)
integer(kind=ilp),	intent(in)			::	incx
real(kind=dp),	intent(inout)			::	dy(*)
integer(kind=ilp),	intent(in)			::	incy
real(kind=dp),	intent(in)			::	dparam(5)