Mark Dow

Geek art

Simple recursive systems and fractal patterns

2x2 2-symbol L-system self-symmetries

    The simplest 2x2 block replacement system patterns.

Thumnail chart
Tiny thumbnail chart
Notes
  

2x2 2-symbol L-system self-symmetry thumbail chart

lists of all systems        pattern chart        average pattern chart        self-symmetry chart (tiny)        Fourier transform chart
one corner first rule bar first rule diagonal first rule three corner first rule all first rule one corner first rule bar first rule diagonal first rule three corner first rule all first rule
none second rule Corner repeat system, link to Period-doubling line system, link to Period-doubling diagonal system, link to Sierpinski right triangle swap system, link to
Blinker system, link to none second rule Corner repeat system, link to Period-doubling line system, link to Period-doubling diagonal system, link to Sierpinski right triangle swap system, link to Blinker system, link to none second rule
one corner second rule Corner periodic system, link toCorner mirror system, link to
Corner rotate system, link to
Bar corner center system, link to
Bar corner edge system, link to
Diagonal corner cross system, link to
Diagonal corner system, link to
Hadamard matrix swap system, link toCorner mirror inverse swap system, link to
Corner symmetric swap system, link to
Four corners system, link to one corner second rule Corner periodic system, link toCorner mirror system, link to
Corner rotate system, link to
Bar corner center system, link to
Bar corner edge system, link to
Diagonal corner cross system, link to
Diagonal corner system, link to
Hadamard matrix swap system, link toCorner mirror inverse swap system, link to
Corner symmetric swap system, link to
Four corners system, link to one corner second rule
bar second rule Corner bar center system, link toCorner bar edge system, link to Thue-Morse line system, link toThue-Morse line system, link to
Bar bar cross system, link to
Diagonal bar system, link to Corner bar center swap system, link toCorner bar edge swap system, link to
Double period-doubling line system, link to bar second rule Corner bar center system, link toCorner bar edge system, link to Stripes system, link toThue-Morse line system, link to
Bar bar cross system, link to
Diagonal bar system, link to Corner bar center swap system, link toCorner bar edge swap system, link to Double period-doubling line system, link to bar second rule
diagonal second rule Corner cross system, link toCorner diagonal system, link to
Bar diagonal system, link to Checkerboard system, link to
Thue-Morse system, link to
Corner cross swap system, link toCorner diagonal swap system, link to Four diagonal system, link to diagonal second rule Corner cross system, link toCorner diagonal system, link to Bar diagonal system, link to Checkerboard system, link to
Thue-Morse system, link to
Corner cross swap system, link toCorner diagonal swap system, link to Four diagonal system, link to diagonal second rule
three corner second rule Hadamard matrix system, link toCorner mirror inverse system, link to
Corner rotate inverse system, link to
Bar corner center swap system, link to
Bar corner edge system, link to
Diagonal corner cross swap system, link to
Diagonal corner swap system, link to
Corner periodic system, link toCorner mirror swap system, link to
Corner rotate swap system, link to
Four period-doubling system, link to three corner second rule Hadamard matrix system, link toCorner mirror inverse system, link to
Corner rotate inverse system, link to 
Bar corner center swap system, link to
Bar corner edge system, link to
Diagonal corner cross swap system, link to
Diagonal corner swap system, link to
Corner periodic system, link toCorner mirror swap system, link to
Corner rotate swap system, link to
Four period-doubling system, link to three corner second rule
all second rule Sierpinski right triangle system, link to Edge line system, link to Diagonal line system, link to Corner repeat swap system, link to On system, link to all second rule Sierpinski right triangle system, link to Edge line system, link to Diagonal line system, link to Corner repeat swap system, link to On system, link to all second rule
one corner first rule bar first rule diagonal first rule three corner first rule all first rule one corner first rule bar first rule diagonal first rule three corner first rule all first rule
lists of all systems        pattern chart        average pattern chart        self-symmetry chart (tiny)        Fourier transform chart

2x2 2-symbol L-system self-symmetry tiny thumbail chart

lists of all systems        pattern chart        average pattern chart        self-symmetry chart (larger)        Fourier transform chart
one corner first rule bar first rule diagonal first rule three corner first rule all first rule one corner first rule bar first rule diagonal first rule three corner first rule all first rule
none second rule Corner repeat system, link to Period-doubling line system, link to Period-doubling diagonal system, link to Sierpinski right triangle swap system, link to
Blinker system, link to none second rule Corner repeat system, link to Period-doubling line system, link to Period-doubling diagonal system, link to Sierpinski right triangle swap system, link to Blinker system, link to none second rule
one corner second rule Corner periodic system, link toCorner mirror system, link to
Corner rotate system, link to
Bar corner center system, link to
Bar corner edge system, link to
Diagonal corner cross system, link to
Diagonal corner system, link to
Hadamard matrix swap system, link toCorner mirror inverse swap system, link to
Corner symmetric swap system, link to
Four corners system, link to one corner second rule Corner periodic system, link toCorner mirror system, link to
Corner rotate system, link to
Bar corner center system, link to
Bar corner edge system, link to
Diagonal corner cross system, link to
Diagonal corner system, link to
Hadamard matrix swap system, link toCorner mirror inverse swap system, link to
Corner symmetric swap system, link to
Four corners system, link to one corner second rule
bar second rule Corner bar center system, link toCorner bar edge system, link to Thue-Morse line system, link toThue-Morse line system, link to
Bar bar cross system, link to
Diagonal bar system, link to Corner bar center swap system, link toCorner bar edge swap system, link to
Double period-doubling line system, link to bar second rule Corner bar center system, link toCorner bar edge system, link to Stripes system, link toThue-Morse line system, link to
Bar bar cross system, link to
Diagonal bar system, link to Corner bar center swap system, link toCorner bar edge swap system, link to Double period-doubling line system, link to bar second rule
diagonal second rule Corner cross system, link toCorner diagonal system, link to
Bar diagonal system, link to Checkerboard system, link to
Thue-Morse system, link to
Corner cross swap system, link toCorner diagonal swap system, link to Four diagonal system, link to diagonal second rule Corner cross system, link toCorner diagonal system, link to Bar diagonal system, link to Checkerboard system, link to
Thue-Morse system, link to
Corner cross swap system, link toCorner diagonal swap system, link to Four diagonal system, link to diagonal second rule
three corner second rule Hadamard matrix system, link toCorner mirror inverse system, link to
Corner rotate inverse system, link to
Bar corner center swap system, link to
Bar corner edge system, link to
Diagonal corner cross swap system, link to
Diagonal corner swap system, link to
Corner periodic system, link toCorner mirror swap system, link to
Corner rotate swap system, link to
Four period-doubling system, link to three corner second rule Hadamard matrix system, link toCorner mirror inverse system, link to
Corner rotate inverse system, link to
Bar corner center swap system, link to
Bar corner edge system, link to
Diagonal corner cross swap system, link to
Diagonal corner swap system, link to
Corner periodic system, link toCorner mirror swap system, link to
Corner rotate swap system, link to
Four period-doubling system, link to three corner second rule
all second rule Sierpinski right triangle system, link to Edge line system, link to Diagonal line system, link to Corner repeat swap system, link to On system, link to all second rule Sierpinski right triangle system, link to Edge line system, link to Diagonal line system, link to Corner repeat swap system, link to On system, link to all second rule
one corner first rule bar first rule diagonal first rule three corner first rule all first rule one corner first rule bar first rule diagonal first rule three corner first rule all first rule
lists of all systems        pattern chart        average pattern chart        self-symmetry chart (larger)        Fourier transform chart

About self-symmetries and their graphical representation

    [To Do]
    What do the self-symmetry diagrams mean?
They illustrate where the system pattern as a whole reappears in part of the system pattern. [To Do: Explain and show examples.] 

    Do the self-symmetry diagrams show all self-symmetries?
No, only the first self-symmetries that don't cross power of two boundaries. [To Do: Explain and show example.]

    [If the first symbol appears in the first rule, that quadrant will be self-similar to the global pattern.]

Notes

    There are 256 different ways of filling the pair of 2x2 rules with one of two symbols ( 256 = 2^(2x2x2)). There are 46 different patterns on this chart. But there's a bit of ambiguity with respect to what constitutes a different pattern. Rotations and inversions (interchange of symbols) are not considered as different patterns.

[To Do: Examples of the following.]

    A first rule that is all black, such that the second rule is never reached, is not included as it is not a two symbol system.

    One pattern is included twice, one the inverse (symbol interchange) of the other. While I don't count this as a unique pattern, the system occurs is properly located in two spots.

    The 0 -> [0,0,0,0], 1 -> [1,1,1,1] system never returns to symbol zero. The pattern is equivalent to its fixed point after the first generation. But it is a proper unique system if the evolution is considered.

[To Do: Alternating mirror and swap symmetries are not always represented. For example the Stripes system global symmetry should be symbol exchange symmetric about the vertical axis. The Thue-Morse system alternates between vertical symmetry and anti-symmetry.]

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