Noble
Polyhedra with 'Ih' (icosahedral) symmetry and 12
gonality
Notes: In
all
cases one representative face has been highlighted. This face
remains solid through the various displays in the VRML
window. Pressing the 'frame' hud button will display a
'framework' version of the figure, 'hull' will then display the
figure with a framework convex hull, 'solid' returns to the initial
view.
gD-22.1
Hull: Great Rhombicosidodecahedron
Gonality / Valence: 12 / 3
V-E-F: 120-180-30
Genus / Wiener Index: 16 / 65990
gD-23.1
Hull: Great Rhombicosidodecahedron
Gonality / Valence: 12 / 3
V-E-F: 120-180-30
Genus / Wiener Index: 16 / 47763
gD-27.1 Hull:
Great
Rhombicosidodecahedron
Gonality / Valence: 12 /
3 V-E-F:
120-180-30 Genus
/ Wiener Index: 16 /39143
The Wiener
Index is more specifically the Geometric Wiener Index, which is the
sum of the shortest paths (along the edges) between any two
vertices. I find it a useful metric as apart from some
duplication in the Kepler-Poinsot cases it gives a unique value for
every noble polyhedron even when truncated to an integer. In
all cases the polyehdra are scaled to a radius of 1 for this
calculation.The topological
Wiener
Index (which is the sum of the number of edges traversed) is
described in wikipedia
and in
Wolfram
Mathworld. The 'geometric' variant used here is an
extension of this using the sum of actual edge
lengths. See Mohar and Pisanski: "How to Compute the
Wiener index of a Graph" https://users.fmf.uni-lj.si/mohar/Reprints/1988/BM88_JMC2_Pisanki_WienerIndex.pdf
For
my generation method, examples with a gonality > 6 were not
practical to generate directly as the number of ways to choose n
vertices from the total became too large. Instead, use was
made of the fact that the dual of a noble polyhedron is also a
noble polyhedron, so the dual of a noble polyhedron with (gonality,
valence) = (m, n) would be a noble polyhedron with (gonality,
valence) = (n, m). The polyhedra above were produced as duals
of noble polyheda with lower gonality.