program mkave
      character*80 f1,f2,s1,fn
      real,allocatable::x(:),yave(:),yactual(:)
      write(6,*)'average of spectra in a list'
      if( iargc().ne.3)then
       write(6,600)
600    format(' usage: mkave <file.lst> <file.prn> <iopt>',/,/,
     1        '      <file.lst> ... file.list',/,
     2        '      <file.prn> ... resultant spectrum',/,
     3        '       iopt ... 0 ... plain average',/,
     4        '                1 ... normalized to first spectrum',/)
       stop
      endif
      call getarg(1,f1)
      call getarg(2,f2)
      call getarg(3,s1)
      read(s1,*)iopt

      n=0
      open(10,file=f1,status='old')
1     read(10,'(a)',end=99,err=99)fn
      n=n+1
      goto 1
99    close(10)
      write(6,*)n,' spectra'
      if(n.lt.1)stop

      open(10,file=f1)
      read(10,'(a)')fn
      close(10)
      write(6,*)fn
      np=0
2     open(11,file=fn,status='old')
      read(11,*,end=88,err=88)xx,y
      np=np+1
      goto 2
88    close(11)
      write(6,*)np,' points'
      if(np.lt.1)stop


      allocate(x(np),yave(np),yactual(np))
      do 3 i=1,np
      x(i)=0.
3     yave(i)=0.

      anorm1=0.
      open(10,file=f1)
      do 4 i=1,n
      read(10,'(a)')fn
      open(11,file=fn)
      anorm=0.
      do 5 j=1,np
      read(11,*)xx,y
      anorm=anorm+abs(y)
5     yactual(j)=y
      close(11)
      if(i.eq.1)then
       anorm1=anorm
      else
       if(iopt.eq.1)then
        do 6 j=1,np
6       yactual(j)=yactual(j)*anorm1/anorm
       endif
      endif
      do 4 j=1,np
4     yave(j)=yave(j)+yactual(j)
      close(10)
      do 7 i=1,np
7     yave(i)=yave(i)/real(n)

      open(10,file=f2)
      do 8 i=1,np
8     write(10,100)x(i),yave(i)
100   format(f12.2,g12.4)
      close(10)

      end