1       DOUBLE PRECISION FUNCTION DZSUM1( N, CX, INCX )
 2 *
 3 *  -- LAPACK auxiliary routine (version 3.2) --
 4 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 5 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 6 *     November 2006
 7 *
 8 *     .. Scalar Arguments ..
 9       INTEGER            INCX, N
10 *     ..
11 *     .. Array Arguments ..
12       COMPLEX*16         CX( * )
13 *     ..
14 *
15 *  Purpose
16 *  =======
17 *
18 *  DZSUM1 takes the sum of the absolute values of a complex
19 *  vector and returns a double precision result.
20 *
21 *  Based on DZASUM from the Level 1 BLAS.
22 *  The change is to use the 'genuine' absolute value.
23 *
24 *  Contributed by Nick Higham for use with ZLACON.
25 *
26 *  Arguments
27 *  =========
28 *
29 *  N       (input) INTEGER
30 *          The number of elements in the vector CX.
31 *
32 *  CX      (input) COMPLEX*16 array, dimension (N)
33 *          The vector whose elements will be summed.
34 *
35 *  INCX    (input) INTEGER
36 *          The spacing between successive values of CX.  INCX > 0.
37 *
38 *  =====================================================================
39 *
40 *     .. Local Scalars ..
41       INTEGER            I, NINCX
42       DOUBLE PRECISION   STEMP
43 *     ..
44 *     .. Intrinsic Functions ..
45       INTRINSIC          ABS
46 *     ..
47 *     .. Executable Statements ..
48 *
49       DZSUM1 = 0.0D0
50       STEMP = 0.0D0
51       IF( N.LE.0 )
52      $   RETURN
53       IF( INCX.EQ.1 )
54      $   GO TO 20
55 *
56 *     CODE FOR INCREMENT NOT EQUAL TO 1
57 *
58       NINCX = N*INCX
59       DO 10 I = 1, NINCX, INCX
60 *
61 *        NEXT LINE MODIFIED.
62 *
63          STEMP = STEMP + ABS( CX( I ) )
64    10 CONTINUE
65       DZSUM1 = STEMP
66       RETURN
67 *
68 *     CODE FOR INCREMENT EQUAL TO 1
69 *
70    20 CONTINUE
71       DO 30 I = 1, N
72 *
73 *        NEXT LINE MODIFIED.
74 *
75          STEMP = STEMP + ABS( CX( I ) )
76    30 CONTINUE
77       DZSUM1 = STEMP
78       RETURN
79 *
80 *     End of DZSUM1
81 *
82       END