dzasum()

double precision function dzasum	(	integer	n,
		complex*16, dimension(*)	zx,
		integer	incx
	)

DZASUM

Purpose:

    DZASUM takes the sum of the (|Re(.)| + |Im(.)|)'s of a complex vector and
    returns a double precision result.

Parameters

[in]	N	N is INTEGER number of elements in input vector(s)
[in,out]	ZX	ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
[in]	INCX	INCX is INTEGER storage spacing between elements of ZX

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Further Details:

     jack dongarra, 3/11/78.
     modified 3/93 to return if incx .le. 0.
     modified 12/3/93, array(1) declarations changed to array(*)

Definition at line 71 of file dzasum.f.

*
*  -- Reference BLAS level1 routine --
*  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
*     .. Scalar Arguments ..
      INTEGER INCX,N
*     ..
*     .. Array Arguments ..
      COMPLEX*16 ZX(*)
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      DOUBLE PRECISION STEMP
      INTEGER I,NINCX
*     ..
*     .. External Functions ..
      DOUBLE PRECISION DCABS1
      EXTERNAL dcabs1
*     ..
      dzasum = 0.0d0
      stemp = 0.0d0
      IF (n.LE.0 .OR. incx.LE.0) RETURN
      IF (incx.EQ.1) THEN
*
*        code for increment equal to 1
*
         DO i = 1,n
            stemp = stemp + dcabs1(zx(i))
         END DO
      ELSE
*
*        code for increment not equal to 1
*
         nincx = n*incx
         DO i = 1,nincx,incx
            stemp = stemp + dcabs1(zx(i))
         END DO
      END IF
      dzasum = stemp
      RETURN
*
*     End of DZASUM
*

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