632/2222[3]

A 3-coloring of the wallpaper group 632 from its index-3 subgroup of type 2222. H is normal in G: it sits inside G in a single way, so there is one coloring by cosets and one by orbits — and they define the same partition.

G
G = 632 — the uncolored pattern: one orbit of the motif p.
632/2222[3].o
632/2222[3].o — coloring by orbits: one color per H-orbit. There is only ever one such coloring.
632/2222[3].1
632/2222[3].1 — coloring by cosets, placement 1.

.ocoloring by orbits gives each H-orbit its own color; it is unique. .1coloring by cosets: H is normal, so there is a single placement and a single coset coloring, and it partitions the pattern exactly as the orbit coloring does. Any picture enlarges on click.

the color group

group G
632 ⟨ a, b, c | a^2, b^3, (a∗b)^6, b∗c ⟩
subgroup H
2222 index 3  ·  generators a (rotation by 1*PI about (0,0)), baB (rotation by 1*PI about (0.375,-0.2165)), Bab (rotation by 1*PI about (0.375,0.2165))
colors
3 one per coset of H, equivalently one per orbit
placements
1 the conjugates of H, [G : NG(H)] — H is normal

how G permutes the colors

generatorcycles
ae
b(0 1 2)
c(0 2 1)

Words act left to right: (a*b)(p) = b(a(p)).

the two families of motions

f1 … f2 — where the motif starts
The motions carrying the motif to the other cells of H’s domain (one cell per H-orbit): f1=B, f2=b.
g1 … g2 — what makes the colors
The coset transversal: gj carries H onto coset j, and the sets H gj are the color classes: g1=b, g2=B.

fundamental domains and pairing transforms

domain tiling symmetries
G
G domain
the fundamental domain of 632
G tiling
the plane tiled by images of G’s domain
G gens
rotation centers of G, the hurricane’s arm count = the order
H
H domain
the fundamental domain of H: a union of 3 cells of G, internal walls shown
H tiling
the plane tiled by H’s domain, over G’s finer tiling
H gens
rotation centers of H = 2222; inequivalent axis classes in shades of the base color

color partitioning

f0.1 f1≡ .1 f2≡ .1 all orbits
orbits of H
H
f1 H
f2 H
all orbits of H
orbits of H g1
H g1
f1 H g1
f2 H g1
all orbits of H g1
orbits of H g2
H g2
f1 H g2
f2 H g2
all orbits of H g2
all colorscoloring by cosets
632/2222[3].1
≡ .1
≡ .1

Each panel is fi H gj: columns are the 3 cells of H’s domain, rows the 3 orbit classes — one color per row, and a full row together is the whole pattern: the right margin shows it as the composition of its 3 orbits, each in its own color — the coloring by orbits .o carried by that row’s gj. H is normal, so every column carries the same coloring — the one marked by the blue frame; the others repeat it with colors relabeled: f1 ≡ .1, f2 ≡ .1. Every panel except H also shows, faded, the set it comes from: H gj panels show H, and fi panels show their row’s H gj. The bottom margin is the coloring by cosets of every column — under a marked column the pictures from the top of the page, under a repeated column the same partition with its colors relabeled (titled its marked twin). Under and over every panel sit faded context layers — the tilings, fundamental domains and symmetry centers of G and H; the ☰ menu at the top right toggles each decoration.