alife_reaction_bz — 2D artificial-life op

Data kinds: imageimage

Call: fullseye.apply(img, "alife_reaction_bz", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

Usage

Belousov-Zhabotinsky-like excitable medium (Greenberg-Hastings automaton).

A 3-state excitable lattice -- 0 = rest, 1 = excited, 2 = refractory -- with

the Greenberg-Hastings rule: an excited cell becomes refractory, a refractory

cell relaxes to rest, and a resting cell fires when at least `thr` of its 8

Moore neighbours are excited. Because a refractory cell cannot be re-excited,

excitation cannot back-propagate and the fronts organise into the travelling

waves and rotating spirals of the BZ reaction. The image tertiles set the

initial state (>2/3 excited, 1/3..2/3 refractory, else rest). `a` sets the

excitation threshold thr = 1 + int(3a) neighbours, `b` the step count

1 + int(20b). Returns state/2.

Detailed usage guide

gallery2d_physics_alife_3d family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

gallery2d_physics_alife_3dpy -3.11 examples/gallery2d_physics_alife_3d.py

sim2real_and_alifepy -3.11 examples/sim2real_and_alife.py

Ops the type connects to (they accept image as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (artificial-life)

alife_gray_scott · alife_turing · alife_life_step · alife_cyclic_ca · alife_perona_malik · alife_curvature_flow · alife_dla · alife_wolfram1d


*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.