anchor.diff:      end do
   
     end subroutine compute_rho
  -  
  +
  +  !> Compute x-velocity profile along z
     subroutine compute_vx(particles, vx)
       type(particle_system_t), intent(in) :: particles
       type(profile_t), intent(inout) :: vx
  
positive.code: 
    end subroutine mpcd_stream_xforce_yzwall
  
    !! Collide a particle in y and z with constant acceleration in x
    !!
    !! Periodic boundary conditions are applied in x
    subroutine yzwall_collision(x0, v0, x, v, im, L, t, bc, g)
  
negative.code: 
    !> Compute the temperature of a mpcd solvent
    !!
    !! \manual{algorithms,temperature-computation}
    function compute_temperature(particles, cells, tz) result(te)
      use hilbert, only : compact_h_to_p
      type(particle_system_t), intent(inout) :: particles
  