There seems to be some inconsistency with the ordering of parameters for ODE functions between phase_plot and StateSpace.dynamics. phase_plot expects a function with signature f(x, t), whereas StateSpace.dynamics and other functions that are meant to be used with scipy.integrate.solve_ivp provide a function with the signature f(t, x) (note that the order of arguments is different).

It would be nice if the order of arguments was consistent, so you could pass functions compatible with scipy.integrate.solve_ivp directly to phase_plot.