anchor.diff:  !--FIND MINIMUM VALUE OF THE DISTANCE IN PHASESPACE
   !----------------------------------------------------------------------
     190 ifipa=0
  -#ifndef STF
  -      if(ntwin.eq.1) then
  -         read(nfile,end=200,iostat=ierro) ia,ifipa,b_tmp,c_tmp,d_tmp,e_tmp,f_tmp,g_tmp,h_tmp,p_tmp
  -
  -         b=real(b_tmp,fPrec)
  -         c=real(c_tmp,fPrec)
  -         d=real(d_tmp,fPrec)
  -         e=real(e_tmp,fPrec)
  -         f=real(f_tmp,fPrec)
  -         g=real(g_tmp,fPrec)
  -         h=real(h_tmp,fPrec)
  -         p=real(p_tmp,fPrec)
  -
  -      elseif(ntwin.eq.2) then
  -         read(nfile,end=200,iostat=ierro) ia,ifipa,b_tmp,c_tmp,d_tmp,e_tmp,f_tmp,g_tmp,h_tmp,p_tmp,ilapa,b_tmp,c1_tmp,d1_tmp,    &
  -     &e1_tmp,f1_tmp,g1_tmp,h1_tmp,p1_tmp
  -
  -         b=real(b_tmp,fPrec)
  -         c=real(c_tmp,fPrec)
  -         d=real(d_tmp,fPrec)
  -         e=real(e_tmp,fPrec)
  -         f=real(f_tmp,fPrec)
  -         g=real(g_tmp,fPrec)
  -         h=real(h_tmp,fPrec)
  -         p=real(p_tmp,fPrec)
  -
  -         c1=real(c1_tmp,fPrec)
  -         d1=real(d1_tmp,fPrec)
  -         e1=real(e1_tmp,fPrec)
  -         f1=real(f1_tmp,fPrec)
  -         g1=real(g1_tmp,fPrec)
  -         h1=real(h1_tmp,fPrec)
  -         p1=real(p1_tmp,fPrec)
  -
  -      endif
  -#else
   !STF case: read tracking data until one reaches right particle.
         if(ntwin.eq.1) then
            read(nfile,end=200,iostat=ierro) ia_stf,ifipa_stf,b_tmp,c_tmp,d_tmp,e_tmp,f_tmp,g_tmp,h_tmp,p_tmp
  
positive.code:          h1=real(h1_tmp,fPrec)
           p1=real(p1_tmp,fPrec)
        endif
  #endif
        if(ierro.gt.0) then
          write(lout,10320) nfile
          goto 550
  
negative.code:         write(lout,10320) nfile
          goto 550
        endif
  
        if((((numl+1)/iskip)/(iab-iaa))/iav.gt.nlya) nstop=iav*nlya
  
        rewind nfile
  
  !-- Bypassing header to read tracking data later
        do i=1,itopa,2
           read(nfile) !One header per particle pair.
        enddo
        sumda(5)=ta(1,1)**2+ta(1,2)**2
        sumda(6)=ta(3,3)**2+ta(3,4)**2
  
  