Particle Filter — Interactive Demo

Identical Twin Experiment · Track a single dot moving in a circle · Deploy on GitHub Pages

Speed Normal
Step 0 / 300
1 · PREDICT Motion Model
Add process noise → cloud spreads out · uniform weights
2 · UPDATE Likelihood
Weight by P(obs|particle) — brighter = closer to sensor reading
3 · RESAMPLE Survival of Fittest
Duplicate high-weight particles · discard low-weight · reset weights
Tracking Error — RMSE converges toward the sensor noise floor (blue dashed line)