What's Next?
Congratulations
You have completed all 15 lessons. You can now solve differential equations numerically — both scalar ODEs and systems — and analyze their qualitative behavior through equilibria and stability.
What to Explore Next
- SciPy --
scipy.integrate.solve_ivpuses adaptive RK45 with error control. It handles stiff equations and automatic step-size selection far beyond what we built here. - Stiff equations -- Some ODEs require implicit methods (like backward Euler or the Runge-Kutta implicit family). Stiffness arises in chemical kinetics, electronics, and more.
- Partial differential equations (PDEs) -- ODEs involve one independent variable (time). PDEs involve space and time: heat equation, wave equation, Navier-Stokes.
- Chaos theory -- The Lorenz system (
dx/dt = σ(y-x), etc.) shows how deterministic ODEs can produce unpredictable, chaotic behavior. - Bifurcation theory -- How equilibria appear, disappear, or change stability as parameters vary.
References
- Differential Equations, Dynamical Systems, and an Introduction to Chaos by Hirsch, Smale, Devaney
- Nonlinear Dynamics and Chaos by Steven Strogatz — the most readable introduction to the subject
- SciPy ODE documentation -- production-grade solvers