Model is underconstrained.
The following variables couldn't be defined:
 * n in component component
 * n_initial in component component
 * d_initial in component component
 * neighbourhood_d_average in component component
 * a in component component
 * b in component component
 * v in component component
 * k in component component
 * h in component component
 * d/dt n in component component
 * d/dt d in component component