scsum1()

real function scsum1	(	integer	n,
		complex, dimension( * )	cx,
		integer	incx )

SCSUM1 forms the 1-norm of the complex vector using the true absolute value.

Download SCSUM1 + dependencies [TGZ] [ZIP] [TXT]

Purpose:

!>
!> SCSUM1 takes the sum of the absolute values of a complex
!> vector and returns a single precision result.
!>
!> Based on SCASUM from the Level 1 BLAS.
!> The change is to use the 'genuine' absolute value.
!> 

Parameters

[in]	N	!> N is INTEGER !> The number of elements in the vector CX. !>
[in]	CX	!> CX is COMPLEX array, dimension (N) !> The vector whose elements will be summed. !>
[in]	INCX	!> INCX is INTEGER !> The spacing between successive values of CX. INCX > 0. !>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

Nick Higham for use with CLACON.

Definition at line 78 of file scsum1.f.

*
*  -- LAPACK auxiliary routine --
*  -- LAPACK 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            CX( * )
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      INTEGER            I, NINCX
      REAL               STEMP
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          abs
*     ..
*     .. Executable Statements ..
*
      scsum1 = 0.0e0
      stemp = 0.0e0
      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
      scsum1 = 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
      scsum1 = stemp
      RETURN
*
*     End of SCSUM1
*

Here is the call graph for this function:

Here is the caller graph for this function: