program vcal
      character*80 s1,s2,s3,s4
      real*8,allocatable::sx(:),sy(:),rx(:),ry(:)
      write(6,*)
      write(6,*)' Replaces x-scale and/or calibrates a spectrum'
      write(6,*)
      if(iargc().ne.4)then
       write(6,*)' Usage: vcal <spectrum.prn> <newspec.prn>',
     1 ' <reference.prn> ic'
       write(6,*)' '
       write(6,*)'      ic = 1: replace x-scale '
       write(6,*)'      ic = 2: calibrate '
       write(6,*)'      ic = 3: replace x-scale and calibrate '
       stop
      endif
      call getarg(1,s1)
      call getarg(2,s2)
      call getarg(3,s3)
      call getarg(4,s4)
      read(s4,*)ic
      open(10,file=s1)
      n=0
1     read(10,*,end=99,err=99)x,y
      n=n+1
      goto 1
99    close(10)
      allocate(sx(n),sy(n),rx(n),ry(n))
      open(10,file=s1)
      do 2 i=1,n
2     read(10,*)sx(i),sy(i)
      close(10)
      write(6,*)' spectrum read, ',n,' points'
      open(10,file=s3)
      do 3 i=1,n
3     read(10,*)rx(i),ry(i)
      close(10)
      write(6,*)' reference read'
      if(ic.eq.1.or.ic.eq.3)write(6,*)' x-calibrated'
      if(ic.eq.2.or.ic.eq.3)write(6,*)' y-corected'
      do 4 i=1,n
      if(ic.eq.1.or.ic.eq.3)sx(i)=rx(i)
4     if(ic.eq.2.or.ic.eq.3)sy(i)=sy(i)*ry(i)
      open(10,file=s2)
      do 5 i=1,n
5     write(10,100)sx(i),sy(i)
100   format(f12.3,2x,g12.6)
      close(10)
      write(6,*)' result written'
      end