man zdrot (Fonctions bibliothèques) - applies a plane rotation, where the cos and sin (c and s) are real and the vectors cx and cy are complex.

NAME

ZDROT - applies a plane rotation, where the cos and sin (c and s) are real and the vectors cx and cy are complex.

SYNOPSIS

SUBROUTINE ZDROT(
N, CX, INCX, CY, INCY, C, S )
INTEGER INCX, INCY, N
DOUBLE PRECISION C, S
COMPLEX*16 CX( * ), CY( * )
INTEGER I, IX, IY
COMPLEX*16 CTEMP
IF( N.LE.0 ) RETURN
IF( INCX.EQ.1 .AND. INCY.EQ.1 ) GO TO 20
IX = 1
IY = 1
IF( INCX.LT.0 ) IX = ( -N+1 )*INCX + 1
IF( INCY.LT.0 ) IY = ( -N+1 )*INCY + 1
DO 10 I = 1, N
CTEMP = C*CX( IX ) + S*CY( IY )
CY( IY ) = C*CY( IY ) - S*CX( IX )
CX( IX ) = CTEMP
IX = IX + INCX
IY = IY + INCY
10 CONTINUE
RETURN
20 CONTINUE
DO 30 I = 1, N
CTEMP = C*CX( I ) + S*CY( I )
CY( I ) = C*CY( I ) - S*CX( I )
CX( I ) = CTEMP
30 CONTINUE
RETURN
END

PURPOSE