anchor.diff:               rho = new_state(i,j,k,URHO)
                px  = new_state(i,j,k,UMX )
                py  = new_state(i,j,k,UMY )
  -             src(i,j,k,UMX)   =         damping_alpha / period * rho * omega * y
  -             src(i,j,k,UMY)   = -1.d0 * damping_alpha / period * rho * omega * x
  -             src(i,j,k,UEDEN) =         damping_alpha / period * omega * ( px * y - py * x ) / (2.d0 * rho)
  +             src(i,j,k,UMX)   =         damping_alpha / rot_period * rho * omega * y
  +             src(i,j,k,UMY)   = -1.d0 * damping_alpha / rot_period * rho * omega * x
  +             src(i,j,k,UEDEN) =         damping_alpha / rot_period * omega * ( px * y - py * x ) / (2.d0 * rho)
              enddo
   
            enddo
  
positive.code:                            src,src_l1,src_l2,src_l3,src_h1,src_h2,src_h3,problo,dx,time,dt)
  
       use meth_params_module, only : NVAR, URHO, UMX, UMY, UEDEN
       use probdata_module   , only : center, period, damping, damping_alpha
       use bl_constants_module
  
       implicit none
  
negative.code: 
       if ( damping ) then
  
         omega = 2.d0 * M_PI / rot_period
  
         do i = lo(1), hi(1)
           x = problo(1) + (dble(i) + HALF) * dx(1) - center(1)
  