This method solves a system of equations and returns the values of
the dependent variables at times or at \(t=0, dt, 2\;dt, ... Tmax\).
xds_solve(pars, Tmax = 365, dt = 1, times = NULL)a list that defines a model
the last time point, run from 0...Tmax
the time interval for outputs
the times
pars an xds object
Note that xde_derivatives dispatches on class(frame)