Generations: Difference between revisions

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{{Glossary}}
'''Generations''' rules are a generalization of [[Life-like cellular automata]] in which live cells can exist in different states, and cells that would die in a 2-state cellular automaton instead advance to the next state. The name "Generations" is due to the conceptualization of this process as cells "getting older" before eventually dying.{{refn|group=note|The name "Generations", and the different states in which cells in Generations rules can exist, should not be confused with the generations (i.e. repeated evolution) of a pattern.}}
'''Generations''' rules are a generalization of [[Life-like cellular automata]] in which live cells can exist in different states, and cells that would die in a 2-state cellular automaton instead advance to the next state. The name "Generations" is due to the conceptualization of this process as cells "getting older" before eventually dying.{{refn|group=note|The name "Generations", and the different states in which cells in Generations rules can exist, should not be confused with the generations (i.e. repeated evolution) of a pattern.}}


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{{LinkGollyHelp|filename=Algorithms/Generations.html|title=Generations}}
{{LinkGollyHelp|filename=Algorithms/Generations.html|title=Generations}}
{{LinkMirek|rullex_gene.html|title=Family: Generations}}
{{LinkMirek|rullex_gene.html|title=Family: Generations}}
[[Category:Algorithms]]

Revision as of 14:00, 22 July 2017

Generations rules are a generalization of Life-like cellular automata in which live cells can exist in different states, and cells that would die in a 2-state cellular automaton instead advance to the next state. The name "Generations" is due to the conceptualization of this process as cells "getting older" before eventually dying.[note 1]

Description

Generations rules are described by rulestrings of the form Bx/Sy/n or y/x/n, an extension of B/S and S/B rulestrings where n is any natural number ≥2. Patterns evolve according to the following rules:

  1. A cell in state 0 ("dead") will advance to state 1 ("get born") in the next generation of the pattern if the number of neighbors in state 1 ("live") in its Moore neighbourhood is present in the rule's birth conditions (Bx).
  2. A cell in state 1 ("live") will:
    1. Remain in state 1 ("survive") in the next generation of the pattern if the number of neighbors in state 1 ("live") in its Moore neighborhood is present in the rule's survival conditions (Sx).
    2. Advance to state 2 ("age") in the next generation of the pattern otherwise.
  3. A cell in state m ≥ 2 will advance to state ((m + 1) mod n) in the next generation of the pattern. In particular, a cell in state n will reset to state 0 ("die").

Any outer-totalistic Life-like cellular automaton with rulestring B.../S... is equivalent to the Generations rule with rulestring B.../S.../C2.

Examples

Main article: List of Generations rules
Rule (B/S/C) Rule (S/B/C equivalent) Name Character Author
B3457/S2367/5 2367/3457/5 Banners exploding Mirek Wójtowicz
B34678/S234/24 234/34678/24 Bloomerang expanding John Elliott
B2/S/3 /2/3 Brian's Brain chaotic Brian Silverman
B378/S124567/4 124567/378/4 Caterpillars chaotic Mirek Wójtowicz
B2/S23/8 23/2/8 Cooties exploding Rudy Rucker
B13/S2/21 2/13/21 Fireworks exploding John Elliott
B34/S12/3 12/34/3 Frogs chaotic Scott Robert Ladd
B45678/S12345/8 12345/45678/8 Lava expanding Mirek Wójtowicz
B458/S012345/3 012345/458/3 Lines stable Anders Starmark
B2/S345/4 345/2/4 Star Wars exploding Mirek Wójtowicz
B2/S3456/6 3456/2/6 Sticks exploding Rudy Rucker
B26/S345/5 345/26/5 Transers exploding John Elliott
B2356/S1456/16 1456/2356/16 Xtasy exploding John Elliott

Software support

Both MCell and Golly support Generations rules, the latter with a maximum of 256 states.

Extensions

Generations rules can, in a straightforward manner, be adapted to von Neumann and hexagonal neighbourhoods and extended to non-totalistic and non-isotropic rules.

Larger than Life rules extend Generations rules to larger neighbourhoods.

Notes

  1. ↑ The name "Generations", and the different states in which cells in Generations rules can exist, should not be confused with the generations (i.e. repeated evolution) of a pattern.

Generations at Golly's online help Family: Generations at Mirek Wójtowicz's Cellebration page