anchor.diff:  
     ! Copy particle data to 1-dim array and go back to meters
     do j=1,napx
  -    rcx(j)  = (xv1(j)-torbx(ie)) /c1e3
  -    rcxp(j) = (yv1(j)-torbxp(ie))/c1e3
  -    rcy(j)  = (xv2(j)-torby(ie)) /c1e3
  -    rcyp(j) = (yv2(j)-torbyp(ie))/c1e3
  -    rcp(j)  = ejv(j)/c1e3
  -    rcs(j)  = zero
  -    part_hit_before_turn(j) = part_hit_turn(j)
  -    part_hit_before_pos(j)  = part_hit_pos(j)
  +    rcx(j)   = (xv1(j)-torbx(ie)) /c1e3
  +    rcxp(j)  = (yv1(j)-torbxp(ie))/c1e3
  +    rcy(j)   = (xv2(j)-torby(ie)) /c1e3
  +    rcyp(j)  = (yv2(j)-torbyp(ie))/c1e3
  +    rcp(j)   = ejv(j)/c1e3
  +    rcs(j)   = zero
  +
       rcx0(j)  = rcx(j)
       rcxp0(j) = rcxp(j)
       rcy0(j)  = rcy(j)
  
positive.code:   real(kind=fPrec) jawLength,jawAperture,jawOffset,jawTilt(2),x_Dump,xpDump,y_Dump,ypDump,s_Dump,   &
      xmax,ymax,calc_aperture,zpj,xmax_pencil,ymax_pencil,xmax_nom,ymax_nom,nom_aperture,     &
      scale_bx,scale_by,c_tilt(2),c_offset,c_aperture,c_rotation,cry_bendangle,cry_tilt,cry_tilt0
  
  #ifdef G4COLLIMATION
    integer :: g4_lostc
    integer :: g4_npart
    integer :: part_hit_flag = 0
    integer :: part_abs_flag = 0
    real(kind=fPrec) x_tmp,y_tmp,xp_tmp,yp_tmp
  
    ! ien0,ien1: ion energy entering/leaving the collimator
    ! energy in MeV
    real(kind=fPrec)    :: ien0, ien1
    integer(kind=int16) :: nnuc0,nnuc1
  #endif
  
    ! Get the aperture from the beta functions and emittance
    ! A simple estimate of beta beating can be included that has twice the betatron phase advance
  
negative.code:       part_abs_pos, part_abs_turn, part_impact, part_indiv, part_linteract,             &
        onesided, nhit_type, 1, nabs_type, linside)
    end if
  #else
    call coll_doCollimator_Geant4(c_aperture,c_rotation)
  #endif
    end if
  
  