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      SUBROUTINE ZAXPY(N,ZA,ZX,INCX,ZY,INCY)
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*     .. Scalar Arguments ..
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      DOUBLE COMPLEX ZA
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      INTEGER INCX,INCY,N
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*     ..
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*     .. Array Arguments ..
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      DOUBLE COMPLEX ZX(*),ZY(*)
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*     ..
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*
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*  Purpose
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*  =======
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*
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*     constant times a vector plus a vector.
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*     jack dongarra, 3/11/78.
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*     modified 12/3/93, array(1) declarations changed to array(*)
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*
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*     .. Local Scalars ..
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      INTEGER I,IX,IY
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*     ..
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*     .. External Functions ..
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      DOUBLE PRECISION DCABS1
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      EXTERNAL DCABS1
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*     ..
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      IF (N.LE.0) RETURN
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      IF (DCABS1(ZA).EQ.0.0d0) RETURN
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      IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20
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*
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*        code for unequal increments or equal increments
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*          not equal to 1
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*
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      IX = 1
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      IY = 1
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      IF (INCX.LT.0) IX = (-N+1)*INCX + 1
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      IF (INCY.LT.0) IY = (-N+1)*INCY + 1
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      DO 10 I = 1,N
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          ZY(IY) = ZY(IY) + ZA*ZX(IX)
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          IX = IX + INCX
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          IY = IY + INCY
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   10 CONTINUE
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      RETURN
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*
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*        code for both increments equal to 1
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*
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   20 DO 30 I = 1,N
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          ZY(I) = ZY(I) + ZA*ZX(I)
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   30 CONTINUE
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      RETURN
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      END