SUBROUTINE DROTM(N,DX,INCX,DY,INCY,DPARAM)
INTEGER INCX,INCY,N
DOUBLE PRECISION DPARAM(5),DX(1),DY(1)
DOUBLE PRECISION DFLAG,DH11,DH12,DH21,DH22,TWO,W,Z,ZERO
INTEGER I,KX,KY,NSTEPS
DATA ZERO,TWO/0.D0,2.D0/
DFLAG = DPARAM(1)
IF (N.LE.0 .OR. (DFLAG+TWO.EQ.ZERO)) GO TO 140
IF (.NOT. (INCX.EQ.INCY.AND.INCX.GT.0)) GO TO 70
NSTEPS = N*INCX
IF (DFLAG) 50,10,30
10 CONTINUE
DH12 = DPARAM(4)
DH21 = DPARAM(3)
DO 20 I = 1,NSTEPS,INCX
W = DX(I)
Z = DY(I)
DX(I) = W + Z*DH12
DY(I) = W*DH21 + Z
20 CONTINUE
GO TO 140
30 CONTINUE
DH11 = DPARAM(2)
DH22 = DPARAM(5)
DO 40 I = 1,NSTEPS,INCX
W = DX(I)
Z = DY(I)
DX(I) = W*DH11 + Z
DY(I) = -W + DH22*Z
40 CONTINUE
GO TO 140
50 CONTINUE
DH11 = DPARAM(2)
DH12 = DPARAM(4)
DH21 = DPARAM(3)
DH22 = DPARAM(5)
DO 60 I = 1,NSTEPS,INCX
W = DX(I)
Z = DY(I)
DX(I) = W*DH11 + Z*DH12
DY(I) = W*DH21 + Z*DH22
60 CONTINUE
GO TO 140
70 CONTINUE
KX = 1
KY = 1
IF (INCX.LT.0) KX = 1 + (1-N)*INCX
IF (INCY.LT.0) KY = 1 + (1-N)*INCY
IF (DFLAG) 120,80,100
80 CONTINUE
DH12 = DPARAM(4)
DH21 = DPARAM(3)
DO 90 I = 1,N
W = DX(KX)
Z = DY(KY)
DX(KX) = W + Z*DH12
DY(KY) = W*DH21 + Z
KX = KX + INCX
KY = KY + INCY
90 CONTINUE
GO TO 140
100 CONTINUE
DH11 = DPARAM(2)
DH22 = DPARAM(5)
DO 110 I = 1,N
W = DX(KX)
Z = DY(KY)
DX(KX) = W*DH11 + Z
DY(KY) = -W + DH22*Z
KX = KX + INCX
KY = KY + INCY
110 CONTINUE
GO TO 140
120 CONTINUE
DH11 = DPARAM(2)
DH12 = DPARAM(4)
DH21 = DPARAM(3)
DH22 = DPARAM(5)
DO 130 I = 1,N
W = DX(KX)
Z = DY(KY)
DX(KX) = W*DH11 + Z*DH12
DY(KY) = W*DH21 + Z*DH22
KX = KX + INCX
KY = KY + INCY
130 CONTINUE
140 CONTINUE
RETURN
END