DOUBLE PRECISION FUNCTION DZNRM2(N,X,INCX)
INTEGER INCX,N
DOUBLE COMPLEX X(*)
DOUBLE PRECISION ONE,ZERO
PARAMETER (ONE=1.0D+0,ZERO=0.0D+0)
DOUBLE PRECISION NORM,SCALE,SSQ,TEMP
INTEGER IX
INTRINSIC ABS,DBLE,DIMAG,SQRT
IF (N.LT.1 .OR. INCX.LT.1) THEN
NORM = ZERO
ELSE
SCALE = ZERO
SSQ = ONE
DO 10 IX = 1,1 + (N-1)*INCX,INCX
IF (DBLE(X(IX)).NE.ZERO) THEN
TEMP = ABS(DBLE(X(IX)))
IF (SCALE.LT.TEMP) THEN
SSQ = ONE + SSQ* (SCALE/TEMP)**2
SCALE = TEMP
ELSE
SSQ = SSQ + (TEMP/SCALE)**2
END IF
END IF
IF (DIMAG(X(IX)).NE.ZERO) THEN
TEMP = ABS(DIMAG(X(IX)))
IF (SCALE.LT.TEMP) THEN
SSQ = ONE + SSQ* (SCALE/TEMP)**2
SCALE = TEMP
ELSE
SSQ = SSQ + (TEMP/SCALE)**2
END IF
END IF
10 CONTINUE
NORM = SCALE*SQRT(SSQ)
END IF
DZNRM2 = NORM
RETURN
END