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DOUBLE PRECISION FUNCTION DZSUM1( 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
* =======
*
* DZSUM1 takes the sum of the absolute values of a complex
* vector and returns a double precision result.
*
* Based on DZASUM from the 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 > 0.
*
* =====================================================================
*
* .. Local Scalars ..
INTEGER I, NINCX
DOUBLE PRECISION STEMP
* ..
* .. Intrinsic Functions ..
INTRINSIC ABS
* ..
* .. Executable Statements ..
*
DZSUM1 = 0.0D0
STEMP = 0.0D0
IF( N.LE.0 )
$ RETURN
IF( INCX.EQ.1 )
$ GO TO 20
*
* CODE FOR INCREMENT NOT EQUAL TO 1
*
NINCX = N*INCX
DO 10 I = 1, NINCX, INCX
*
* NEXT LINE MODIFIED.
*
STEMP = STEMP + ABS( CX( I ) )
10 CONTINUE
DZSUM1 = STEMP
RETURN
*
* CODE FOR INCREMENT EQUAL TO 1
*
20 CONTINUE
DO 30 I = 1, N
*
* NEXT LINE MODIFIED.
*
STEMP = STEMP + ABS( CX( I ) )
30 CONTINUE
DZSUM1 = STEMP
RETURN
*
* End of DZSUM1
*
END
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