alife_sandpile — 2D `artificial-life` op

• 数据种类:image → image

• 调用:fullseye.apply(img, "alife_sandpile", a=0.5, b=0.5)(2-D 的模型是一张图 + 两个标量旋钮 a,b∈[0,1])

阿贝尔沙堆模型(Abelian sandpile)/自组织临界性(self-organised criticality,Bak-Tang-Wiesenfeld 1987)。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

The image is quantised to integer grain heights h = round(K * image) with

K = 4 + int(12a), then relaxed by the BTW toppling rule: a cell with 4 or

more grains gives one grain to each orthogonal neighbour and keeps the rest.

The boundary is dissipative (grains leaving the grid are lost), which is what

lets the pile settle into the self-organised critical state where every cell

holds at most 3 grains.

`a` sets the initial grain scale K (how supercritical the pile starts);

`b` sets the number of parallel relaxation sweeps 1 + int(50b). For

b >= 0.9 the pile relaxes *toward* stability with early termination, but the

sweep count is bounded by a total-work budget (`_SANDPILE_BUDGET` grain-

updates) so the op stays fast on any image size: a small or varied pile

reaches the stable critical state (every cell <= 3), while a very large

maximally-supercritical pile is only partially relaxed (full BTW

stabilisation is O(L^2) sweeps). Returns h / max(h) in [0, 1]; a fully

relaxed pile (max 3) takes values in {0, 1/3, 2/3, 1} (or {0, 1/2, 1} when

the stable maximum is 2).

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

• 算法的正典(作者・年份)与用途见上面的族使用指南。

• gallery2d_physics_alife_3d — py -3.11 examples/gallery2d_physics_alife_3d.py

*Provenance: ops.py — 2D 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

alife_sandpile — 2D artificial-life op