SUBROUTINE graf_s(start, delta, psi, npts, filename, nds, ider)
USE Numeric_Kinds_Module
!-----------------------------------------------------------------------
! This routine was written by G. A. Parker
! IF you find an error or have an improvement please send a messge to
! parker@phyast.nhn.uoknor.edu 
!-----------------------------------------------------------------------
IMPLICIT NONE
INTEGER, PARAMETER :: Graf_Unit=39
CHARACTER(len=*) :: filename
INTEGER  :: npts, ip, nds, nstart, ider, istat
REAL(dp) :: start, delta, psi(nds:npts)
REAL(sp) :: xval, pltf

!----------------------------------------------------------------------- 
! outputs results for subsequent plotting.
!-----------------------------------------------------------------------

nstart=0

OPEN(UNIT=Graf_Unit,FILE=filename,IOSTAT=istat,STATUS='replace',ACTION='write')
IF (istat.ne.0) STOP 'OPEN failed - graf_s'
IF(nds.eq.1)THEN
   nstart=1
ELSE IF(nds.eq.0)THEN
   nstart=-npts
ELSE
   STOP 'Graf'
ENDIF

DO ip=nstart,npts
   xval=start+(ip-1)*delta
   IF(ip.lt.0)THEN
      pltf=psi(-ip)*(-1)**ider
   ELSE
      pltf=psi(ip)
   ENDIF
   WRITE(Graf_Unit,'(1x,6(1pe14.6,","))')xval,pltf
ENDDO
CLOSE(Unit=Graf_Unit,IOSTAT=istat,STATUS='keep')
IF (istat.ne.0) STOP 'CLOSE failed - graf_s'

RETURN
END SUBROUTINE graf_s