Which of a pattern's symmetries its letterings keep
A generator in the designing a base library, called 6 times across 1 essay. Below: what it draws with nothing specified and with the settings the essays give it, what it checked while drawing, and everywhere it is used.
pattern-symmetry is one function. Everything below was drawn by it when the site was
last published, at settings taken from the essays rather than invented for this page — so a figure
here is the same figure a reader meets in an essay, and when the generator changes, this
page changes with it.
With nothing specified
view: "kept", pattern: "preliminary-base"
view: "kept", pattern: "square-twist"
view: "halves"
What it checked while it drew
Collected while it drew, not written by hand.
The count is how many separate times that claim was put to the test.
2 of the 8 symmetries of the square twist are kept by none of its 256 letterings ×1
3 of the 8 symmetries of the preliminary base are kept by none of its 112 letterings ×1
both patterns are carried to themselves by all eight symmetries of the square, so the comparison holds the drawing's group fixed and varies only the letters ×1
every node of the straight skeleton is equidistant from each edge that defined it, so one fold serves them all — 1 checked ×1
patterns too large to enumerate are sampled and said to be, because a sample can show a symmetry is sometimes kept and can never show it never is ×1
the pattern's symmetries are found by carrying its vertex set and edge set onto themselves, and the letterings are enumerated separately, so the two columns are independent computations ×1
Where it is called
Every figure listed here is drawn by the same rule, so a mistake in the rule would be in all
of them at once, and so would a correction.