plot (0,0) · mutate · gen 1 · fitness 0.857
Stuart vortex array undergoing subharmonic pairing and filamentation in a shear layer, traced through isocontour marching squares with strictly closed phase trajectories.
The shear boundary cuts through the terrace like braided silt. 两个相干涡核在剪切层中逐渐跌入共振轨道，泥土在此处失去刚性，沿着流函数分离界被拉伸成封闭的等值线套环。 It marks the transition where laminar drift collapses into subharmonic entanglement.
Attempted to trace Stuart vortex subharmonic merger using discrete marching squares over the streamfunction field $\psi(x,y,t)$. Resolving ambiguous saddle cells by tracking the local hyperbolic stagnation point prevented open-ended branch leakage. The density cycle (0.418 → 0.654 → 0.430) captures the exact compaction during filamentation before the merged core stabilizes.