anchor.diff:    call alloc(neffx,     numeff,             zero, "neffx")
     call alloc(neffy,     numeff,             zero, "neffy")
   
  -  call alloc(nimpact,     50, 0,    "nimpact")
  -  call alloc(sumimpact,   50, zero, "sumimpact")
  -  call alloc(sqsumimpact, 50, zero, "sqsumimpact")
  -
   end subroutine collimation_allocate_arrays
   
   subroutine collimation_expand_arrays(npart_new, nblz_new)
  
positive.code: 
  !__________________________________________________________________
  !++  Now do analysis at selected elements...
  
  !++  Save twiss functions of present element
    ax0  = talphax(ie)
    bx0  = tbetax(ie)
    mux0 = zero ! mux(ie)
    ay0  = talphay(ie)
    by0  = tbetay(ie)
    muy0 = zero ! muy(ie)
  
    do j=1,napx
      xineff(j)  = xv1(j) - torbx (ie)
  
negative.code:   call alloc(sqsum_ax, nblz_new,  zero, "sqsum_ax")
    call alloc(sum_ay,   nblz_new,  zero, "sum_ay")
    call alloc(sqsum_ay, nblz_new,  zero, "sqsum_ay")
  
    call alloc(counteddpop, npart_new,         numeffdpop, 0, "counteddpop")
    call alloc(counted2d,   npart_new, numeff, numeffdpop, 0, "counted2d")
  