Visual calculus / Java roots / Browser precision
See an integral
take shape.
Draw a function, split an interval and watch two numerical methods close in on the same answer. The maths stays visible, including the error.
Live workbench
Change the inputs.
The drawing answers.
No account, backend or tracking. Every calculation runs in this page.
Calculation ready.
Parse
A small expression parser accepts a deliberate maths vocabulary. It never calls JavaScript evaluation.
Approximate
Exactly N intervals feed the midpoint and trapezoidal rules. Signed area stays signed.
Compare
A high-resolution Simpson calculation provides a reference, so the error is visible instead of implied.
2023 → now
The idea survived.
The shortcuts did not.
The original Swing prototype made numerical integration visible. This rebuild keeps that idea and replaces the brittle parts around it.
- Desktop
- Java 17, code-built Swing UI, executable Maven JAR and JUnit coverage.
- Browser
- Strict TypeScript, Canvas rendering and a dependency-free expression engine.
- Math
- Correct interval counts, signed areas, bounded rendering and explicit validation.
- Delivery
- Automated tests for both implementations and a reproducible GitHub Pages build.
Project record
Built together.
Reworked in the open.
IntegraDraw began as a collaborative school project in 2023. Djenis Ejupi and other project contributors built the original Java prototype.
Djenis leads the current modernization. Earlier work is credited collectively without publishing individual contributor identities.