# dlar2v (l) - Linux Manuals

## NAME

DLAR2V - applies a vector of real plane rotations from both sides to a sequence of 2-by-2 real symmetric matrices, defined by the elements of the vectors x, y and z

## SYNOPSIS

SUBROUTINE DLAR2V(
N, X, Y, Z, INCX, C, S, INCC )

INTEGER INCC, INCX, N

DOUBLE PRECISION C( * ), S( * ), X( * ), Y( * ), Z( * )

## PURPOSE

DLAR2V applies a vector of real plane rotations from both sides to a sequence of 2-by-2 real symmetric matrices, defined by the elements of the vectors x, y and z. For i = 1,2,...,n
x(i)  z(i) :=  c(i)  s(i) x(i)  z(i) c(i) -s(i) )
z(i)  y(i)    -s(i)  c(i) z(i)  y(i) s(i)  c(i) )

## ARGUMENTS

N (input) INTEGER
The number of plane rotations to be applied.
X (input/output) DOUBLE PRECISION array,
dimension (1+(N-1)*INCX) The vector x.
Y (input/output) DOUBLE PRECISION array,
dimension (1+(N-1)*INCX) The vector y.
Z (input/output) DOUBLE PRECISION array,
dimension (1+(N-1)*INCX) The vector z.
INCX (input) INTEGER
The increment between elements of X, Y and Z. INCX > 0.
C (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
The cosines of the plane rotations.
S (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
The sines of the plane rotations.
INCC (input) INTEGER
The increment between elements of C and S. INCC > 0.