Difference between revisions of "Generations"

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[[Larger than Life]] rules extend Generations rules to larger neighbourhoods.
[[Larger than Life]] rules extend Generations rules to larger neighbourhoods.
"snoitareneG" rules, in which cells take time to become alive, have been explored.<ref>http://www.conwaylife.com/forums/viewtopic.php?f=11&t=2939</ref>


==Notes==
==Notes==

Revision as of 15:04, 1 August 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/Cn[note 2] 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/C5 2367/3457/5 Banners Exploding Mirek Wójtowicz
B34678/S234/C24 234/34678/24 Bloomerang Expanding John Elliott
B2/S/C3 /2/3 Brian's Brain Chaotic Brian Silverman
B378/S124567/C4 124567/378/4 Caterpillars Chaotic Mirek Wójtowicz
B2/S23/C8 23/2/8 Cooties Exploding Rudy Rucker
B13/S2/C21 2/13/21 Fireworks Exploding John Elliott
B34/S12/C3 12/34/3 Frogs Chaotic Scott Robert Ladd
B45678/S12345/C8 12345/45678/8 Lava Expanding Mirek Wójtowicz
B458/S012345/C3 012345/458/3 Lines Stable Anders Starmark
B2/S345/C4 345/2/4 Star Wars Exploding Mirek Wójtowicz
B2/S3456/C6 3456/2/6 Sticks Exploding Rudy Rucker
B26/S345/C5 345/26/5 Transers Exploding John Elliott
B2356/S1456/C16 1456/2356/16 Xtasy Exploding John Elliott

Software support

Both MCell and Golly support Generations rules, the latter with a maximum of 256 states. Generations rules are also supported by Chris Rowett's LifeViewer starting with build 180.

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.

"snoitareneG" rules, in which cells take time to become alive, have been explored.[1]

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.
  2. "C" stands for "Count" (of cell states); alternatively, "G" (for "Generations") may be used.

External links

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