```      SUBROUTINE ZLASSQ( N, X, INCX, SCALE, SUMSQ )
*
*  -- LAPACK auxiliary routine (version 3.1) --
*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
*     November 2006
*
*     .. Scalar Arguments ..
INTEGER            INCX, N
DOUBLE PRECISION   SCALE, SUMSQ
*     ..
*     .. Array Arguments ..
COMPLEX*16         X( * )
*     ..
*
*  Purpose
*  =======
*
*  ZLASSQ returns the values scl and ssq such that
*
*     ( scl**2 )*ssq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq,
*
*  where x( i ) = abs( X( 1 + ( i - 1 )*INCX ) ). The value of sumsq is
*  assumed to be at least unity and the value of ssq will then satisfy
*
*     1.0 .le. ssq .le. ( sumsq + 2*n ).
*
*  scale is assumed to be non-negative and scl returns the value
*
*     scl = max( scale, abs( real( x( i ) ) ), abs( aimag( x( i ) ) ) ),
*            i
*
*  scale and sumsq must be supplied in SCALE and SUMSQ respectively.
*  SCALE and SUMSQ are overwritten by scl and ssq respectively.
*
*  The routine makes only one pass through the vector X.
*
*  Arguments
*  =========
*
*  N       (input) INTEGER
*          The number of elements to be used from the vector X.
*
*  X       (input) COMPLEX*16 array, dimension (N)
*          The vector x as described above.
*             x( i )  = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n.
*
*  INCX    (input) INTEGER
*          The increment between successive values of the vector X.
*          INCX > 0.
*
*  SCALE   (input/output) DOUBLE PRECISION
*          On entry, the value  scale  in the equation above.
*          On exit, SCALE is overwritten with the value  scl .
*
*  SUMSQ   (input/output) DOUBLE PRECISION
*          On entry, the value  sumsq  in the equation above.
*          On exit, SUMSQ is overwritten with the value  ssq .
*
* =====================================================================
*
*     .. Parameters ..
DOUBLE PRECISION   ZERO
PARAMETER          ( ZERO = 0.0D+0 )
*     ..
*     .. Local Scalars ..
INTEGER            IX
DOUBLE PRECISION   TEMP1
*     ..
*     .. Intrinsic Functions ..
INTRINSIC          ABS, DBLE, DIMAG
*     ..
*     .. Executable Statements ..
*
IF( N.GT.0 ) THEN
DO 10 IX = 1, 1 + ( N-1 )*INCX, INCX
IF( DBLE( X( IX ) ).NE.ZERO ) THEN
TEMP1 = ABS( DBLE( X( IX ) ) )
IF( SCALE.LT.TEMP1 ) THEN
SUMSQ = 1 + SUMSQ*( SCALE / TEMP1 )**2
SCALE = TEMP1
ELSE
SUMSQ = SUMSQ + ( TEMP1 / SCALE )**2
END IF
END IF
IF( DIMAG( X( IX ) ).NE.ZERO ) THEN
TEMP1 = ABS( DIMAG( X( IX ) ) )
IF( SCALE.LT.TEMP1 ) THEN
SUMSQ = 1 + SUMSQ*( SCALE / TEMP1 )**2
SCALE = TEMP1
ELSE
SUMSQ = SUMSQ + ( TEMP1 / SCALE )**2
END IF
END IF
10    CONTINUE
END IF
*
RETURN
*
*     End of ZLASSQ
*
END

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