Fig 4. Spatial hybrid vs. Fokker-Planck formulation in the limit of large D.
Probability density function of dimensionless continuous variable ρ is shown for t = 30 s, sufficient for accurate approximation of the system’s steady state. Results from VCell hybrid (dots) are based on 10,000 realizations, and Fokker-Planck equations (Eq (4)) were solved by VCell fully implicit advection-diffusion solver with mesh size Δρ/ρmax = 0.004 (solid curve). The L2-norm of the difference between the two solutions is 0.0137.