FORCED VDP · ≤650 · DRAG PAN · PINCH ZOOM · TAP SEED
REDUCED MOTION · SETTLED ATTRACTOR
a
1.0
SPEED (dt)
0.02
FADE
0.08
PRESETS
Forced Van der Pol — ẋ=y, ẏ=a(1−x²)y−x+0.5 cos z, ż=1. Phase-wrap z. Classic a=1. Distinct from van-der-pol.html / mathieu-vanderpol.html. RK4. Gold trail, cap 650. RM = settled silhouette, no animate-on.