```      INTEGER          FUNCTION IZMAX1( N, CX, INCX )
*
*  -- LAPACK auxiliary routine (version 3.1) --
*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
*     November 2006
*
*     .. Scalar Arguments ..
INTEGER            INCX, N
*     ..
*     .. Array Arguments ..
COMPLEX*16         CX( * )
*     ..
*
*  Purpose
*  =======
*
*  IZMAX1 finds the index of the element whose real part has maximum
*  absolute value.
*
*  Based on IZAMAX from Level 1 BLAS.
*  The change is to use the 'genuine' absolute value.
*
*  Contributed by Nick Higham for use with ZLACON.
*
*  Arguments
*  =========
*
*  N       (input) INTEGER
*          The number of elements in the vector CX.
*
*  CX      (input) COMPLEX*16 array, dimension (N)
*          The vector whose elements will be summed.
*
*  INCX    (input) INTEGER
*          The spacing between successive values of CX.  INCX >= 1.
*
* =====================================================================
*
*     .. Local Scalars ..
INTEGER            I, IX
DOUBLE PRECISION   SMAX
COMPLEX*16         ZDUM
*     ..
*     .. Intrinsic Functions ..
INTRINSIC          ABS
*     ..
*     .. Statement Functions ..
DOUBLE PRECISION   CABS1
*     ..
*     .. Statement Function definitions ..
*
*     NEXT LINE IS THE ONLY MODIFICATION.
CABS1( ZDUM ) = ABS( ZDUM )
*     ..
*     .. Executable Statements ..
*
IZMAX1 = 0
IF( N.LT.1 )
\$   RETURN
IZMAX1 = 1
IF( N.EQ.1 )
\$   RETURN
IF( INCX.EQ.1 )
\$   GO TO 30
*
*     CODE FOR INCREMENT NOT EQUAL TO 1
*
IX = 1
SMAX = CABS1( CX( 1 ) )
IX = IX + INCX
DO 20 I = 2, N
IF( CABS1( CX( IX ) ).LE.SMAX )
\$      GO TO 10
IZMAX1 = I
SMAX = CABS1( CX( IX ) )
10    CONTINUE
IX = IX + INCX
20 CONTINUE
RETURN
*
*     CODE FOR INCREMENT EQUAL TO 1
*
30 CONTINUE
SMAX = CABS1( CX( 1 ) )
DO 40 I = 2, N
IF( CABS1( CX( I ) ).LE.SMAX )
\$      GO TO 40
IZMAX1 = I
SMAX = CABS1( CX( I ) )
40 CONTINUE
RETURN
*
*     End of IZMAX1
*
END

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