anchor.diff:    ! Determine the original location of the center.
   
     if (dim .eq. 3) then
  -  
  +
        center(1) = problo(1) + center_fracx * (probhi(1) - problo(1))
        center(2) = problo(2) + center_fracy * (probhi(2) - problo(2))
        center(3) = problo(3) + center_fracz * (probhi(3) - problo(3))
  
positive.code:               else
                   grav_force_S = mass_S / r_S
                endif
                
                if (grav_force_P > ZERO .and. grav_force_P > grav_force_S) then
                   volp = volp + vol(i,j,k)
                else if (grav_force_S > ZERO .and. grav_force_S > grav_force_P) then
                   vols = vols + vol(i,j,k)
                endif
               
             endif
  
          enddo
  
negative.code:            else
                grav_force_P = mass_P / r_P
             endif
  
             if (mass_S == ZERO .or. mass_S < 1.d-12 * mass_P) then
                grav_force_S = ZERO
             else
                grav_force_S = mass_S / r_S
             endif
  
             if (grav_force_P > ZERO .and. grav_force_P > grav_force_S) then
  
                m_p = m_p + dm
  