Frequently asked questions
What is this site?
ODEPLOT plots direction fields, integral curves, phase portraits, 3D trajectories, PDE characteristics and variational extremals in the browser.
Do I need an account?
No. Enter an equation and click the field.
Where are formulas stored?
In your browser localStorage. They are not sent to our server. Clearing site data removes history and theme.
How do parameter sliders appear?
Letters in the expression (e.g. a*x + b*y) that are not x, y or standard functions become sliders.
Which integrator?
Explicit 4th-order Runge–Kutta (RK4). It is numerical, not a symbolic closed form.
Why are there ads?
Slots fund hosting. CIS visitors get Yandex YAN; everyone else gets Google AdSense. Ads do not change the math. See the cookie policy.
Language and theme?
RU / EN / BY in the header. The sun/moon icon toggles theme. Both are saved in localStorage.
Can I download an image?
Canvas pages offer PNG export and a shareable link with the equation.
How can I support the project?
The contacts page has USDT (BEP-20 / TRC-20), email, and contributions of examples.
It is slow on a phone?
The layout is responsive, but 3D scenes need more memory. Close extra tabs or use a desktop for heavy sections.