NAME¶

ZLACRT - performs the operation ( c s )( x ) ==> ( x ) ( -s c )( y ) ( y ) where c and s are complex and the vectors x and y are complex

SYNOPSIS¶

SUBROUTINE ZLACRT(

N, CX, INCX, CY, INCY, C, S )

INTEGER INCX, INCY, N COMPLEX*16 C, S COMPLEX*16 CX( * ), CY( * )

PURPOSE¶

ZLACRT performs the operation

ARGUMENTS¶

N (input) INTEGER

The number of elements in the vectors CX and CY.

CX (input/output) COMPLEX*16 array, dimension (N)

On input, the vector x. On output, CX is overwritten with c*x + s*y.

INCX (input) INTEGER

The increment between successive values of CX. INCX <> 0.

CY (input/output) COMPLEX*16 array, dimension (N)

On input, the vector y. On output, CY is overwritten with -s*x + c*y.

INCY (input) INTEGER

The increment between successive values of CY. INCY <> 0.

C (input) COMPLEX*16

S (input) COMPLEX*16 C and S define the matrix [ C S ]. [ -S C ]