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En route vers la 4.4.1.

    1:       DOUBLE COMPLEX FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
    2: *     .. Scalar Arguments ..
    3:       INTEGER INCX,INCY,N
    4: *     ..
    5: *     .. Array Arguments ..
    6:       DOUBLE COMPLEX ZX(*),ZY(*)
    7: *     ..
    8: *
    9: *  Purpose
   10: *  =======
   11: *
   12: *     ZDOTU forms the dot product of two vectors.
   13: *
   14: *  Further Details
   15: *  ===============
   16: *
   17: *     jack dongarra, 3/11/78.
   18: *     modified 12/3/93, array(1) declarations changed to array(*)
   19: *
   20: *  =====================================================================
   21: *
   22: *     .. Local Scalars ..
   23:       DOUBLE COMPLEX ZTEMP
   24:       INTEGER I,IX,IY
   25: *     ..
   26:       ZTEMP = (0.0d0,0.0d0)
   27:       ZDOTU = (0.0d0,0.0d0)
   28:       IF (N.LE.0) RETURN
   29:       IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
   30: *
   31: *        code for both increments equal to 1
   32: *
   33:          DO I = 1,N
   34:             ZTEMP = ZTEMP + ZX(I)*ZY(I)
   35:          END DO
   36:       ELSE
   37: *
   38: *        code for unequal increments or equal increments
   39: *          not equal to 1
   40: *
   41:          IX = 1
   42:          IY = 1
   43:          IF (INCX.LT.0) IX = (-N+1)*INCX + 1
   44:          IF (INCY.LT.0) IY = (-N+1)*INCY + 1
   45:          DO I = 1,N
   46:             ZTEMP = ZTEMP + ZX(IX)*ZY(IY)
   47:             IX = IX + INCX
   48:             IY = IY + INCY
   49:          END DO
   50:       END IF
   51:       ZDOTU = ZTEMP
   52:       RETURN
   53:       END