program sorder
      implicit none
      real*8 x,y
      integer*4 i,j,n,npmax,np
      logical lex
      character*80 s80
      real*8,allocatable::xs(:,:),ys(:,:)
      integer*4,allocatable::nps(:)
      logical,allocatable::scale(:)
      write(6,600)
600   format(/,' Put spectra in SLIST.TXT to SLIST.PRN',/,
     1         ' just to make Sigmaplot import easier',/)
      inquire(file='SLIST.TXT',exist=lex)
      if(.not.lex)then
       write(6,*)'SLIST.TXT not found'
       stop
      endif
      n=0
      npmax=0
      open(9,file='SLIST.TXT')
1     read(9,900,end=99,err=99)s80 
900   format(a80)
      open(10,file=s80)
      np=0
2     read(10,*,end=88,err=88)x,y
      np=np+1
      goto 2
88    close(10)
      if(np.gt.npmax)npmax=np
      n=n+1
      goto 1
99    close(9)
      write(6,*)n,' spectra, maximal number of points:',npmax

      allocate(xs(n,npmax),ys(n,npmax),nps(n),scale(n))

      open(9,file='SLIST.TXT')
      do 3 i=1,n
      read(9,900)s80 
      open(10,file=s80)
      np=0
4     read(10,*,end=77,err=77)x,y
      np=np+1
      xs(i,np)=x
      ys(i,np)=y
      goto 4
77    close(10)
3     nps(i)=np
      write(6,*)'spectra loaded'

c     does it have the same scale as previous spectrum:
      scale(1)=.false.
      do 7 i=2,n
7     scale(i)=nps(i).eq.nps(i-1).and.xs(i,1).eq.xs(i-1,1).and.
     1xs(i,2).eq.xs(i-1,2).and.xs(i,nps(i)).eq.xs(i-1,nps(i-1))

      write(6,*)scale

      open(9,file='SLIST.PRN')
      do 5 j=1,npmax
      do 6 i=1,n
      if(j.le.nps(i))then
       x=xs(i,j)
       y=ys(i,j)
      else
       x=0.0d0
       y=0.0d0
      endif
      if(scale(i))then
       write(9,902)y
902    format(E12.4,$)
      else
       write(9,901)x,y
901    format(f12.2,E12.4,$)
      endif
6     continue
5     write(9,*)
      close(9)
      write(6,*)'SLIST.PRN written'

      end