Octahedron 5-Compound

Author

Eric W. Weisstein
September 26, 2023

This notebook downloaded from http://mathworld.wolfram.com/notebooks/Polyhedra/Octahedron5-Compound.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/Octahedron5-Compound.html.

©2023 Wolfram Research, Inc. except for portions noted otherwise

Stellation variants

variants={{"OctahedronFiveCompound",1},{"OctahedronFiveCompoundHull",1},{"IcosahedronStellation",3}}

GraphicsRow[Graphics3D[{PolyhedronData[#,"Polyhedron"]},Boxed->False]&/@variants]

PolyhedronData[#,"FaceCount"]&/@variants

Length[PolyhedronData[#,"Polyhedra"]]&/@variants

Variants

variants=Most@PolyhedronData["OctahedronFiveCompound*"]

PolyhedronData[#,"FaceCount"]&/@variants

Length[PolyhedronData[#,"Polyhedra"]]&/@variants

Polyhedra

GraphicsGrid[Transpose[{
Graphics3D[{PolyhedronData[#,"Polyhedron"]},Boxed->False],
With[{poly=PolyhedronData[#,"Polyhedra"]},Graphics3D[Table[{Hue[(i/(Length[poly]))],poly[[i]]},{i,Length[poly]}],Boxed->False]]
}&/@variants],Dividers->All,ImageSize->500]

Solids and duals

GraphicsGrid[
Table[
With[
{
s={Yellow,PolyhedronData[pname,"Midsphere"]},
dname=PolyhedronData[pname,"Dual","Name"],
style=Directive[Black,Italic,FontFamily->"Times",14]
},
{
Graphics3D[{s,Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},Boxed->False,PlotLabel->TextCell[Style[PolyhedronData[pname,"Name"],style],PageWidth->200,TextAlignment->Center]],

Graphics3D[{s,Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},Boxed->False,PlotLabel->Style[PolyhedronData[dname,"Name"],style]],

Graphics3D[{
{Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},
{Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},
s
},Boxed->False,PlotLabel->Style["compound with midsphere",style]],

Graphics3D[{
PolyhedronData[pname,"Polyhedron"],
PolyhedronData[pname,"Dual","Polyhedron"]
},Boxed->False,PlotLabel->Style["compound",style]]
}],
{pname,variants}
],
Dividers->All,ImageSize->800,Alignment->Top
]

Interior and convex hull

GraphicsGrid[
With[{style=Directive[Black,Italic,FontFamily->"Times",16]},
Table[{
Graphics3D[PolyhedronData[pname,"Polyhedron"],PlotLabel->TextCell[Style[PolyhedronData[pname,"Name"],style],PageWidth->200,TextAlignment->Center],Boxed->False],
Graphics3D[{AbsoluteThickness[.5],PolyhedronData[pname,"Lines"],Opacity[.8],PolyhedronData[pname,"CompoundInterior","Polyhedron"]},PlotLabel->Style["interior",style],Boxed->False],
Graphics3D[{
{EdgeForm[None],PolyhedronData[pname,"Polyhedron"]},
{Opacity[.7],EdgeForm[Thickness[.005]],PolyhedronData[pname,"ConvexHull","Polyhedron"]}},PlotLabel->Style["convex hull",style],Boxed->False]
},
{pname,variants}]
],
Dividers->All,ImageSize->700]

TextGrid[
Prepend[
Table[{
pname,
RecognizeGraph@PolyhedronGraph@PolyhedronData[pname,"CompoundInterior","Polyhedron"],
RecognizeGraph@PolyhedronGraph@PolyhedronData[pname,"ConvexHull","Polyhedron"]
},
{pname,variants}],
Thread[Style[{"compound","interior","convex hull"},Bold]]],
Dividers->All]

Properties: {"IcosahedronStellation", 3}

p=PolyhedronData[{"IcosahedronStellation",3},"Polyhedron"]

Centroid

PolyhedronData[{"IcosahedronStellation",3},"Centroid"]

RegionCentroid[p]/PolyhedronData[{"IcosahedronStellation",3},"Volume"]//N

PolyhedronCentroid[p,PolyhedronData[{"IcosahedronStellation",3},"Volume"]]

Circumsphere

PolyhedronData[{"IcosahedronStellation",3},"Circumsphere"]

Norm/@PolyhedronData[{"IcosahedronStellation",3},"VertexCoordinates"]//FullSimplify//Union

DihedralAngles

Tally[PolyhedronData[{"IcosahedronStellation",3},"DihedralAngles"]]

di=SimplifyNumericallyDistinct[DihedralAngles[p],"Simplification"->RootReduce,Debug->True]//Union

EdgeLengths

PolyhedronData[{"IcosahedronStellation",3},"EdgeLengths"]

InertiaTensor

PolyhedronData[{"IcosahedronStellation",3},"InertiaTensor"]

N[%]

MomentOfInertia[p//N,{0,0,0}]/PolyhedronData[{"IcosahedronStellation",3},"Volume"]//Chop

PolyhedronInertiaTensor[p//N,PolyhedronData[{"IcosahedronStellation",3},"Volume"]]//Chop

Orientation

Graphics3D[{FaceForm[Green,Red],PolyhedronData["DodecahedronSmallTriambicIcosahedronCompoundHull","Polyhedron"]}]

SurfaceArea

PolyhedronData[{"IcosahedronStellation",3},"SurfaceArea"]

N[%]

SurfaceArea[p]//N

SurfaceArea[p]//FullSimplify//Timing

PolyhedronSurfaceArea[p]//N

PolyhedronSurfaceArea[p]//FullSimplify//Timing

Volume

PolyhedronData[{"IcosahedronStellation",3},"Volume"]

N[%]

Volume[p]//N

Volume[p]//FullSimplify//Timing

PolyhedronVolume[p]//N

PolyhedronVolume[p]//FullSimplify//Timing

PolyhedronVolume[p,Method->"GaussLaw"]//N

PolyhedronVolume[p,Method->"GaussLaw"]//FullSimplify

Polyhedron: {"OctahedronFiveCompound", 1}

Orientations

PolyhedronData[{"OctahedronFiveCompound", 1},"Orientations"]

PolyhedronData[{"OctahedronFiveCompound", 1}]

Show[PolyhedronData[{{"OctahedronFiveCompound", 1},#}],Boxed->False]&/@PolyhedronData[{"OctahedronFiveCompound", 1},"Orientations"]

Polyhedron

Graphics3D[{FaceForm[Green,Red],PolyhedronData[{"OctahedronFiveCompound", 1},"Polyhedron"]}]

Region

PolyhedronData[{"OctahedronFiveCompound", 1},"Region"]

Solid and dual

PolyhedronData[{"OctahedronFiveCompound", 1},#]&/@{"Graphics3D","Dual","DualCompound"}

Graphics3D[{{Opacity[.4],
Red,PolyhedronData[{"OctahedronFiveCompound", 1},"Polyhedron"],
Green,PolyhedronData[{"OctahedronFiveCompound", 1},"Dual","Polyhedron"]},
Yellow,PolyhedronData[{"OctahedronFiveCompound", 1},"Midsphere"]},Boxed->False]

Polyhedron: {"OctahedronFiveCompound", 2}

Orientations

PolyhedronData[{"OctahedronFiveCompound",2},"Orientations"]

PolyhedronData[{"OctahedronFiveCompound",2}]

Show[PolyhedronData[{{"OctahedronFiveCompound",2},#}],Boxed->False]&/@PolyhedronData[{"OctahedronFiveCompound",2},"Orientations"]

Polyhedron

Graphics3D[{Opacity[.3],PolyhedronData[{"OctahedronFiveCompound",2},"Polyhedron"]}]

Face orientation

Graphics3D[{FaceForm[Green,Red],PolyhedronData[{"OctahedronFiveCompound",2},"Polyhedron"]}]

Region

PolyhedronData[{"OctahedronFiveCompound",2},"Region"]

Solid and dual

PolyhedronData[{"OctahedronFiveCompound",2},#]&/@{"Graphics3D","Dual","DualCompound"}

Graphics3D[{Opacity[.6],
Red,PolyhedronData[{"OctahedronFiveCompound",2},"Polyhedron"],
Green,PolyhedronData[{"OctahedronFiveCompound",2},"Dual","Polyhedron"],
Yellow,PolyhedronData[{"OctahedronFiveCompound",2},"Midsphere"]},Boxed->False]

Properties: {"OctahedronFiveCompound", 1}

Initialization

<<MathWorld`Polyhedra`

p=PolyhedronData[pname={"OctahedronFiveCompound", 1},"Polyhedron"]

AdjacentFaceIndices

adj1=PolyhedronData[pname,"AdjacentFaceIndices"]

adj2=AdjacentFaceIndices[p]

adj1===adj2

Centroid

PolyhedronData[pname,"Centroid"]

Circumsphere

sphere=PolyhedronData[pname,"Circumsphere"]

sphere=Circumsphere[p]

(sphere=MyCircumsphere[p]//RootReduce)//Timing

Graphics3D[{{Opacity[.2],Yellow,sphere},p},Boxed->False]

Classes

PolyhedronData[pname,"Classes"]

Compound

PolyhedronData[pname,"Compound"]

CompoundInterior

intname=PolyhedronData[pname,"CompoundInterior","Name"]

PolyhedronData[pname,"CompoundInterior","Scale"]

PolyhedronData[pname,"CompoundInterior","RotationMatrix"]

PolyhedronData[pname,"CompoundInterior"]

Graphics3D[{
AbsoluteThickness[1],PolyhedronData[pname,"Lines"],
Opacity[.8],interior=PolyhedronData[pname,"CompoundInterior","Polyhedron"]},Boxed->False]

Graphics3D[{{Opacity[.2],p},Red,interior},Boxed->False]

SimplifyNumericallyDistinct[PolyhedronEdgeLengths[interior]]//Counts

MyCircumsphere[interior]//Quiet

Insphere[interior]/.x_?NumericQ:>ToAlgebraicRoot[x]//Quiet

Midsphere[interior]

Construction

int=RegionIntersection[Sequence@@PolyhedronData[pname,"Polyhedra"],PerformanceGoal->"Quality"]

Graphics3D[int]

Graphics3D[{{Opacity[.2],p},Red,int},Boxed->False]

RecognizeGraph@PolyhedronGraph@int

Union[Chop@int[[1]]]//Length

Exactify

vexact=DeleteDuplicates[RootApproximant[Chop[int[[1]]]]]

Length[vexact]

inthull=ConvexHullRegion[Union@vexact]

v=inthull[[1]]//FullSimplify//ToRadicals

faces=inthull[[2]]

gname=RecognizeGraph@PolyhedronGraph[inthull]

GraphData[gname,"PolyhedralEmbeddings"]

SimplifyNumericallyDistinct[PolyhedronEdgeLengths[inthull]]//Counts//Quiet

Find rotation matrix

intname="Icosahedron";

basesolid=PolyhedronData[intname,"Polyhedron"];

s=(Sqrt[7-3 (Sqrt[5])]);

{Graphics3D[{{FaceForm[],LabelPolyhedron[p,Background->LightBlue]},
LabelPolyhedron@Polyhedron[newv=s#&/@basesolid[[1]],basesolid[[2]]]},Boxed->False],
Graphics3D[{{FaceForm[],p},Red,int},Boxed->False]}

{,}

lines={Line[p[[1,{23,5}]]],Line[p[[1,{22,29}]]]}

RegionDistance@@lines

wrong

bug(440618): RegionDistance[line, line2] incorrectly returns non-zero machine-precision result

LineLineDistance@@lines//RootReduce//Quiet

RegionIntersection@@lines

bug(440619): RegionIntersection[line1, line2] hangs (for exact coordinates) and returns EmptyRegion[3] (for numeric coordinates)

(mid=First[Intersection3D@@lines//RootReduce])//Quiet//Timing

Graphics3D[{{FaceForm[],LabelPolyhedron[p,Background->LightBlue]},
LabelPolyhedron@Polyhedron[newv=s#&/@basesolid[[1]],basesolid[[2]]],
Thick,lines,AbsolutePointSize[12],Point[mid]
},Boxed->False]

rot=RotationMatrix[{basesolid[[1,5]],mid//ToRadicals}];

Graphics3D[{{FaceForm[],LabelPolyhedron[p,Background->LightGreen]},
LabelPolyhedron@Polyhedron[newv2=s RotationMatrix[Pi/5,mid].rot.#&/@basesolid[[1]],basesolid[[2]]],
Thick,lines,AbsolutePointSize[12],Point[mid]
},Boxed->False]

Map[ToAlgebraicRoot,RotationMatrix[Pi/5,mid].rot,{2}]//Quiet

Concave

PolyhedronData[pname,"Concave"]

Convex

PolyhedronData[pname,"Convex"]

ConvexPolyhedronQ[p]//Timing

ConvexHull

convexhullname=PolyhedronData[pname,"ConvexHull","Name"]

PolyhedronData[pname,"ConvexHull","Scale"]

PolyhedronData[pname,"ConvexHull","RotationMatrix"]

Graphics3D[convexhull=PolyhedronData[pname,"ConvexHull","Polyhedron"]]

{
Graphics3D[{Red,Opacity[.5],p}],
Graphics3D[{Blue,Opacity[.5],convexhull}]
}

Show[%]

Construct using ConvexHullRegion

Graphics3D[convexhullreg=ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]

v=PolyhedronCoordinates[convexhullreg]

Sort[(convexhullreg[[2]]/.i_Integer:>v[[i]])/.Thread[PolyhedronData[pname,"Vertices"]->Range[PolyhedronData[pname,"V"]]]]

Find scale

SimplifyNumericallyDistinct[PolyhedronEdgeLengths[convexhullreg]]//Tally//FullSimplify

((Max[Norm/@p[[1]]])/(Max[Norm/@PolyhedronData[convexhullname,"Polyhedron"][[1]]]))//FullSimplify//Quiet

ConvexHullOf

hullof=DeleteCases[Select[PolyhedronData[All],PolyhedronData[#,"ConvexHullName"]===pname&],pname]

DehnInvariant

PolyhedronData[pname,"DehnInvariant"]

(dehn=DehnInvariant[p,Debug->True]//FullSimplify)//Timing

ToConwayBasis[dehn]

Complement[Select[PolyhedronData[All],PolyhedronData[#,"DehnInvariant"]==dehn&&PolyhedronData[#,"Volume"]==vol&],{pname}]

DihedralAngles

(dih1=PolyhedronData[pname,"DihedralAngles"])//Tally

(dih2=SimplifyNumericallyDistinct[DihedralAngles[p]])//Tally

dih1===dih2

Dual

pname

dname=PolyhedronData[pname,"Dual","Name"]

PolyhedronData[pname,"Dual","Scale"]

midrs={PolyhedronData[pname,"Midradius"],PolyhedronData[dname,"Midradius"]}

Divide@@midrs//FullSimplify

GraphicsRow[With[{
s={Yellow,PolyhedronData[pname,"Midsphere"]},
style=Directive[Black,Italic,FontFamily->"Times",14]
},
{
Graphics3D[{s,Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},Boxed->False,PlotLabel->TextCell[Style[PolyhedronData[pname,"Name"],style],PageWidth->200,TextAlignment->Center]],
Graphics3D[{s,Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},Boxed->False,PlotLabel->Style[PolyhedronData[dname,"Name"],style]],
Graphics3D[{
{Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},
{Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},
s
},Boxed->False,PlotLabel->Style["compound with midsphere",style]],
Graphics3D[{
PolyhedronData[pname,"Polyhedron"],
PolyhedronData[pname,"Dual","Polyhedron"]
},Boxed->False,PlotLabel->Style["compound",style]]
}],Alignment->Top,ImageSize->800]

OctahedronDual[oct_Polyhedron]:=ConvexHullRegion[((1/2) (-1+(Sqrt[5])))(Sqrt[6])Mean[#[[1]][[#[[2]]]]]&/@PolyhedronPolygons[oct]]

OctahedronDual/@PolyhedronData[pname,"Polyhedra"]

Graphics3D[{PolyhedronData[pname,"Polyhedra"],OctahedronDual/@PolyhedronData[pname,"Polyhedra"]}]

EdgeCount

PolyhedronData[pname,"EdgeCount"]

EdgeLengths

Tally[lens=SimplifyNumericallyDistinct[PolyhedronEdgeLengths[p],"Simplification"->RootReduce]//FullSimplify]//Timing

PolyhedronData[pname,"EdgeLengths"]

PolyhedronData[pname,"Lines"]/.Line[l_]:>EuclideanDistance@@l//FullSimplify//Union//Quiet

(distinctlens=Mean/@Split[Sort[lens],Abs[#1-#2]<1.*^-10&])//N//Quiet

v=p[[1]];

colors=With[{n=Length[distinctlens]},Table[Hue[i/n],{i,0,n-1}]]

Graphics3D[{Thick,Sequence@@Nearest[Thread[distinctlens->colors],EuclideanDistance@@v[[#]]],Line[v[[#]]]}&/@PolyhedronEdges[p],Boxed->False]//Quiet

FaceCount

PolyhedronData[pname,"FaceCount"]

GeneralizedDiameter

PolyhedronData[pname,"GeneralizedDiameter"]

GeneralizedDiameter[p]//FullSimplify//Quiet

Hull

hullname=PolyhedronData[pname,"Hull","Name"]

PolyhedronData[pname,"Hull","Scale"]

((Max[Norm/@p[[1]]])/(Max[Norm/@PolyhedronData[hullname,"Polyhedron"][[1]]]))//FullSimplify//Quiet

PolyhedronData[pname,"Hull"]

Max[Norm/@PolyhedronData[pname,"Hull","Polyhedron"][[1]]]//FullSimplify//Quiet

Max[Norm/@p[[1]]]//FullSimplify//Quiet

{Graphics3D[{Opacity[.5],Red,p}],Graphics3D[{Opacity[.5],Blue,PolyhedronData[pname,"Hull"][[1]]}]}

Show[%]

HullOf

Select[PolyhedronData[All],PolyhedronData[#,"HullName"]===pname&]

Select[PolyhedronData[All],PolyhedronData[#,"HullName"]===hullname&]

InertiaTensor

PolyhedronData[pname,"InertiaTensor"]

Insphere

PolyhedronData[pname,"Insphere"]

Insphere[p]

(sphere=MyInsphere[p])//Timing

MeanCylindricalRadius

PolyhedronData[pname,"MeanCylindricalRadius"]

MeanSquareCylindricalRadius

PolyhedronData[pname,"MeanSquareCylindricalRadius"]

MeanSphericalRadius

PolyhedronData[pname,"MeanSphericalRadius"]

MeanSquareSphericalRadius

PolyhedronData[pname,"MeanSquareSphericalRadius"]

Midsphere

sphere=PolyhedronData[pname,"Midsphere"]

Midsphere[p//N]

(sphere=Midsphere[p])//Timing

(sphere=Midsphere[p,Method->"PointLineDistance"])//Timing

Graphics3D[{{Opacity[.5],Yellow,p},{Red,sphere}},Boxed->False]

Net

PolyhedronData[pname,"Net"]

NotationRules

PolyhedronData[pname,"NotationRules"]

Orientations

PolyhedronData[pname,"Orientations"]

PolyhedronData[pname,"DefaultOrientation"]

Show[PolyhedronData[{pname,#}],Boxed->False]&/@PolyhedronData[pname,"Orientations"]

Polygons

PolyhedronData[pname,"FaceCount"]

PolyhedronFaceTally[p]

Graphics3D/@PolyhedronData[pname,"Polygons"]

Show[%]

Polyhedra

polyhedra=PolyhedronData[pname,"Polyhedra"]

Length[polyhedra]

Graphics3D[polyhedra]

Graphics3D[Table[{Hue[(i/(Length[polyhedra]))],polyhedra[[i]]},{i,Length[polyhedra]}]]

PolyhedronData[pname,"PolyhedronIndices"]

Region

PolyhedronData[pname,"Region"]

RegionFunction

PolyhedronData[pname,"RegionFunction"]

SimplePolyhedron

PolyhedronData[pname,"Simple"]

SimplePolyhedronQ[p]//Timing

Skeleton

PolyhedronData[pname,"Skeleton"]

gn=PolyhedronData[pname,"Skeleton","Name"]

GraphData[gn]

emb=GraphData[gn,"PolyhedralEmbeddings"]

GraphData[gn,"Graph",{"3D","All"}]

g=PolyhedronGraph[p]

SurfaceArea

PolyhedronData[pname,"SurfaceArea"]

SurfaceArea[p]

Total[Area/@PolyhedronData[pname,"Polygons"]]//ToAlgebraicRoot

SurfaceArea[PolyhedronData[pname,"Region"]]

Uniform

PolyhedronData[pname,"Uniform"]

VertexCount

PolyhedronData[pname,"VertexCount"]

VertexSubsetHulls

subsethulls=PolyhedronData[pname,"VertexSubsetHulls"]

v=PolyhedronData[pname,"Vertices"];

Rule[#,Length[#2]]&@@@subsethulls

Rule[#,Graphics3D[Function[f,ConvexHullRegion[v[[f]]]]/@#2]]&@@@subsethulls

subsethulls2=Flatten[Function[{pn,l},Rule[pn,#]&/@l]@@@subsethulls]

Rule[#,Graphics3D[{{Opacity[.3],{Green,p}},Blue,ConvexHullRegion[v[[#2]]]}]]&@@@subsethulls2

Convex hull

Graphics3D[convexhullreg=ConvexHullRegion[v=PolyhedronData[pname,"Vertices"]]]

v=PolyhedronCoordinates[convexhullreg]

Flatten[(convexhullreg[[2]]/.i_Integer:>v[[i]])/.Thread[PolyhedronData[pname,"Vertices"]->Range[PolyhedronData[pname,"V"]]]]//Union

%===Range@Length@v

PolyhedronData[pname,"ConvexHull","Name"]

Platonic

(h=VertexSubsetHulls[p,"Platonic","Skip"->{}])//Timing

Volume

PolyhedronData[pname,"Volume"]

WythoffSymbol

PolyhedronData[pname,"WythoffSymbol"]

Properties: {"OctahedronFiveCompoundHull", 1}

Initialization

<<MathWorld`Polyhedra`

p=PolyhedronData[pname="OctahedronFiveCompoundHull","Polyhedron"]

vol=PolyhedronData[pname,"Volume"]

AdjacentFaceIndices

adj1=PolyhedronData[pname,"AdjacentFaceIndices"]

adj2=AdjacentFaceIndices[p]

adj1===adj2

Centroid

PolyhedronData[pname,"Centroid"]

Graphics3D[{AbsolutePointSize[10],
Point[{0,0,0}],{Blue,Point[PolyhedronData[pname,"Centroid"]]},Opacity[.2],PolyhedronData[pname,"GraphicsComplex"]}]

RegionCentroid[p]

PolyhedronCentroid[p]

Circumsphere

sphere=PolyhedronData[pname,"Circumsphere"]

sphere=Circumsphere[p]

(sphere=MyCircumsphere[p])//Timing

Graphics3D[{{Opacity[.2],Yellow,sphere},p},Boxed->False]

Classes

PolyhedronData[pname,"Classes"]

Compound

PolyhedronData[pname,"Compound"]

Concave

PolyhedronData[pname,"Concave"]

Convex

PolyhedronData[pname,"Convex"]

ConvexPolyhedronQ[p]

ConvexHull

convexhullname=PolyhedronData[pname,"ConvexHull","Name"]

PolyhedronData[pname,"ConvexHull","Scale"]

PolyhedronData[pname,"ConvexHull","RotationMatrix"]

Graphics3D[convexhull=PolyhedronData[pname,"ConvexHull","Polyhedron"]]

{
Graphics3D[{Red,Opacity[.5],p}],
Graphics3D[{Blue,Opacity[.5],convexhull}]
}

Show[%]

Construct using ConvexHullRegion

Graphics3D[convexhullreg=ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]

v=PolyhedronCoordinates[convexhullreg]

Sort[(convexhullreg[[2]]/.i_Integer:>v[[i]])/.Thread[PolyhedronData[pname,"Vertices"]->Range[PolyhedronData[pname,"V"]]]]

Find scale

SimplifyNumericallyDistinct[PolyhedronEdgeLengths[convexhullreg]]//Tally//FullSimplify

((Max[Norm/@p[[1]]])/(Max[Norm/@PolyhedronData[convexhullname,"Polyhedron"][[1]]]))//FullSimplify//Quiet

Find rotation matrix

Graphics3D[{FaceForm[Green,Red],basesolid=PolyhedronData[convexhullname,"Polyhedron"],MapIndexed[Text[#2[[1]],#,Background->White]&,basev=basesolid[[1]]]}]

rot=RotationMatrix[{Mean[basev[[{11,12}]]],{0,0,1}}]//FullSimplify

{Graphics3D[{Polyhedron[newv=rot.#&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

ArcTan@@(Most@Mean[newv[[{7,29}]]])//FullSimplify

rot2=RotationMatrix[Pi/2+2Pi/5,{0,0,1}].rot//FullSimplify

{Graphics3D[{Polyhedron[(rot2.#)&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

ConvexHullOf

hullof=DeleteCases[Select[PolyhedronData[All],PolyhedronData[#,"ConvexHullName"]===pname&],pname]

GraphicsGrid[Partition[Graphics3D[{
{Green,Opacity[.7],PolyhedronData[#,"Polyhedron"]},
{Blue,Opacity[.2],PolyhedronData[#,"ConvexHull","Polyhedron"]}},Boxed->False,PlotLabel->Style[PolyhedronData[#,"Name"],Directive[14,Black,Italic,FontFamily->"Times"]]]&/@hullof,UpTo[3]],Dividers->All,ImageSize->800]

DehnInvariant

PolyhedronData[pname,"DehnInvariant"]

(dehn=DehnInvariant[p,Debug->True]//FullSimplify)//Timing

ToConwayBasis[dehn]

Complement[Select[PolyhedronData[All],PolyhedronData[#,"DehnInvariant"]==dehn&&PolyhedronData[#,"Volume"]==vol&],{pname}]

DihedralAngles

(dih1=PolyhedronData[pname,"DihedralAngles"])//Tally

(dih2=SimplifyNumericallyDistinct[DihedralAngles[p]])//Tally

dih1===dih2

Dual

pname

dname=PolyhedronData[pname,"Dual","Name"]

PolyhedronData[pname,"Dual","Scale"]

midrs={PolyhedronData[pname,"Midradius"],PolyhedronData[dname,"Midradius"]}

Divide@@midrs//FullSimplify

GraphicsRow[With[{
s={Yellow,PolyhedronData[pname,"Midsphere"]},
style=Directive[Black,Italic,FontFamily->"Times",14]
},
{
Graphics3D[{s,Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},Boxed->False,PlotLabel->TextCell[Style[PolyhedronData[pname,"Name"],style],PageWidth->200,TextAlignment->Center]],
Graphics3D[{s,Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},Boxed->False,PlotLabel->Style[PolyhedronData[dname,"Name"],style]],
Graphics3D[{
{Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},
{Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},
s
},Boxed->False,PlotLabel->Style["compound with midsphere",style]],
Graphics3D[{
PolyhedronData[pname,"Polyhedron"],
PolyhedronData[pname,"Dual","Polyhedron"]
},Boxed->False,PlotLabel->Style["compound",style]]
}],Alignment->Top,ImageSize->800]

EdgeCount

PolyhedronData[pname,"EdgeCount"]

EdgeLengths

Tally[lens=SimplifyNumericallyDistinct[PolyhedronEdgeLengths[p],"Simplification"->RootReduce]//FullSimplify]//Timing

PolyhedronData[pname,"EdgeLengths"]

PolyhedronData[pname,"Lines"]/.Line[l_]:>EuclideanDistance@@l//FullSimplify//Union//Quiet

(distinctlens=Mean/@Split[Sort[lens],Abs[#1-#2]<1.*^-10&])//N//Quiet

v=p[[1]];

colors=With[{n=Length[distinctlens]},Table[Hue[i/n],{i,0,n-1}]]

Graphics3D[{Thick,Sequence@@Nearest[Thread[distinctlens->colors],EuclideanDistance@@v[[#]]],Line[v[[#]]]}&/@PolyhedronEdges[p],Boxed->False]//Quiet

FaceCount

PolyhedronData[pname,"FaceCount"]

GeneralizedDiameter

PolyhedronData[pname,"GeneralizedDiameter"]

GeneralizedDiameter[p]//FullSimplify//Quiet

Hull

hullname=PolyhedronData[pname,"Hull","Name"]

PolyhedronData[pname,"Hull","Scale"]

((Max[Norm/@p[[1]]])/(Max[Norm/@PolyhedronData[hullname,"Polyhedron"][[1]]]))//FullSimplify//Quiet

PolyhedronData[pname,"Hull"]

Max[Norm/@PolyhedronData[pname,"Hull","Polyhedron"][[1]]]

Max[Norm/@p[[1]]]

{Graphics3D[{Opacity[.5],Red,p}],Graphics3D[{Opacity[.5],Blue,PolyhedronData[pname,"Hull"][[1]]}]}

Show[%]

Find rotation matrix

Graphics3D[{FaceForm[Green,Red],basesolid=PolyhedronData[hullname,"Polyhedron"],MapIndexed[Text[#2[[1]],#,Background->White]&,basev=basesolid[[1]]]}]

rot=RotationMatrix[{Mean[basev[[{11,12}]]],{0,0,1}}]//FullSimplify

{Graphics3D[{Polyhedron[newv=rot.#&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

ArcTan@@(Most@Mean[newv[[{7,29}]]])//FullSimplify

rot2=RotationMatrix[Pi/2+2Pi/5,{0,0,1}].rot//FullSimplify

{Graphics3D[{Polyhedron[(rot2.#)&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

HullOf

Select[PolyhedronData[All],PolyhedronData[#,"HullName"]===pname&]

Select[PolyhedronData[All],PolyhedronData[#,"HullName"]===hullname&]

InertiaTensor

PolyhedronData[pname,"InertiaTensor"]

(i=((MomentOfInertia[p,{0,0,0}])/vol))//Timing

Map[ToAlgebraicRoot,i,{2}]

PolyhedronInertiaTensor[p]//Timing

Insphere

PolyhedronData[pname,"Insphere"]

Insphere[p]

sphere=MyInsphere[p]

Graphics3D[{{Opacity[.5],p},{Red,sphere}},Boxed->False]

MeanCylindricalRadius

PolyhedronData[pname,"MeanCylindricalRadius"]

N[%]

((NIntegrate[(Sqrt[(x^2)+(y^2)]),{x,y,z}∈p])/vol)

ClosestMeanCylindricalRadius[%]

Integrate over polyhedron

(rxy=((Integrate[(Sqrt[(x^2)+(y^2)]),{x,y,z}∈p])/vol)//FullSimplify)

N[rxy]

Divergence theorem

(rxy=MeanCylindricalRadius[p,"Simplification"->FullSimplify,Debug->True])//Timing

N[rxy]

LogSimplify[rxy]//FullSimplify

CAD

cad=CylindricalDecomposition[PolyhedronData[pname,"RegionFunction"][x,y,z],{x,y,z},"Function"]

((NIntegrate[(Sqrt[(x^2)+(y^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol)

(rxy=((Integrate[(Sqrt[(x^2)+(y^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol))//Timing

CAD over  1/10

reg=FullSimplify[PolyhedronData[pname,"RegionFunction"][x,y,z]&&0<y<Tan[Pi/5]x]

cad=CylindricalDecomposition[reg,{x,y,z},"Function"]

10((NIntegrate[(Sqrt[(x^2)+(y^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol)

(rxy=10((Integrate[(Sqrt[(x^2)+(y^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol))//Timing

N[rxy]

LogSimplify[rxy]//FullSimplify

Boole Integrate doing z integral first

{{xmin,xmax},{ymin,ymax},{zmin,zmax}}==CoordinateBounds[p]

ineq=PolyhedronData[pname,"RegionFunction"][x,y,z]

(i1=Integrate[Boole[ineq](Sqrt[(x^2)+(y^2)]),{z,zmin,zmax}])//Timing

NIntegrate[(i1/vol),{x,xmin,xmax},{y,ymin,ymax}]

(i2=Integrate[(i1/vol),{x,xmin,xmax},{y,ymin,ymax}])//Timing

MeanSquareCylindricalRadius

PolyhedronData[pname,"MeanSquareCylindricalRadius"]

N[%]

((NIntegrate[(x^2)+(y^2),{x,y,z}∈p])/vol)

Integrate over Polyhedron

(rxy2=((Integrate[(x^2)+(y^2),{x,y,z}∈p])/vol)//FullSimplify)

N[rxy2]

Divergence theorem

(rxy2=MeanSquareCylindricalRadius[p,"Simplification"->FullSimplify,Debug->True])//Timing

MeanSphericalRadius

PolyhedronData[pname,"MeanSphericalRadius"]

((NIntegrate[(Sqrt[(x^2)+(y^2)+(z^2)]),{x,y,z}∈p])/vol)

ClosestMeanSphericalRadius[%]

Integrate over polyhedron

(rxyz=((Integrate[(Sqrt[(x^2)+(y^2)+(z^2)]),{x,y,z}∈p])/vol))//Timing

N[rxyz]

Divergence theorem

(rxyz=MeanSphericalRadius[p,"Simplification"->FullSimplify,Debug->True])//Timing

N[rxyz]

LogSimplify[rxyz]//FullSimplify

CAD

cad=CylindricalDecomposition[PolyhedronData[pname,"RegionFunction"][x,y,z],{x,y,z},"Function"]

((NIntegrate[(Sqrt[(x^2)+(y^2)+(z^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol)

(rxyz=((Integrate[(Sqrt[(x^2)+(y^2)+(z^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol))//Timing

N[rxyz,20]

rxysimp1=ResourceFunction["LogSimplify"][rxy]//FullSimplify

CAD over  1/10

reg=FullSimplify[PolyhedronData[pname,"RegionFunction"][x,y,z]&&0<y<Tan[Pi/5]x]

cad=CylindricalDecomposition[reg,{x,y,z},"Function"]

10((NIntegrate[(Sqrt[(x^2)+(y^2)+(z^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol)

(rxyz=10((Integrate[(Sqrt[(x^2)+(y^2)+(z^2)])Boole[cad],{x,y,z}∈FullRegion[3]])/vol))//Timing

N[rxyz,20]

rxysimp1=LogSimplify[rxy]//FullSimplify

Boole Integrate doing z integral first

{{xmin,xmax},{ymin,ymax},{zmin,zmax}}=CoordinateBounds[p]

ineq=PolyhedronData[pname,"RegionFunction"][x,y,z]

(i1=Integrate[Boole[ineq](Sqrt[(x^2)+(y^2)+(z^2)]),{z,zmin,zmax}])//Timing

NIntegrate[(i1/vol),{x,xmin,xmax},{y,ymin,ymax}]

(i2=Integrate[(i1/vol),{x,xmin,xmax},{y,ymin,ymax}])//Timing

MeanSquareSphericalRadius

PolyhedronData[pname,"MeanSquareSphericalRadius"]

((NIntegrate[(x^2)+(y^2)+(z^2),{x,y,z}∈p])/vol)

Integrate over polyhedron

(rxy2=((Integrate[(x^2)+(y^2)+(z^2),{x,y,z}∈p])/vol)//FullSimplify)

N[rxy2]

Integrate over region

reg=PolyhedronData[pname,"RegionFunction"][x,y,z]

(rxy=((Integrate[((x^2)+(y^2)+(z^2))Boole[reg],{x,y,z}∈FullRegion[3]])/vol))

Divergence theorem

(rxy2=MeanSquareSphericalRadius[p,"Simplification"->FullSimplify,Debug->True])//Timing

Boole Integrate doing z integral first

{{xmin,xmax},{ymin,ymax},{zmin,zmax}}==CoordinateBounds[p]

ineq=PolyhedronData[pname,"RegionFunction"][x,y,z]

(i1=Integrate[Boole[ineq]((x^2)+(y^2)+(z^2)),{z,zmin,zmax}])//Timing

NIntegrate[(i1/vol),{x,xmin,xmax},{y,ymin,ymax}]

(i2=Integrate[(i1/vol),{x,xmin,xmax},{y,ymin,ymax}])//Timing

Midsphere

sphere=PolyhedronData[pname,"Midsphere"]

Midsphere[p//N]

(sphere=Midsphere[p])//Timing

(sphere=Midsphere[p,Method->"PointLineDistance"])//Timing

Graphics3D[{{Opacity[.5],Yellow,p},{Red,sphere}},Boxed->False]

Net

PolyhedronData[pname,"Net"]

Total[Area/@Flatten[PolyhedronData[pname,"Net","Polygon"]]]//ToAlgebraicRoot//Timing

PolyhedronData[pname,"SurfaceArea"]

poly3d=PolyhedronData[pname,"Net","Polygons"]/.Polygon[v_]:>Polygon[Append[#,0]&/@v]

Total[Area/@Flatten[poly3d]]//RootReduce//FullSimplify

Graphics3D[{FaceForm[Green,Red],poly3d},Axes->True,AxesLabel->{"x","y","z"}]

NotationRules

PolyhedronData[pname,"NotationRules"]

Orientations

PolyhedronData[pname,"Orientations"]

PolyhedronData[pname,"DefaultOrientation"]

Show[PolyhedronData[{pname,#}],Boxed->False]&/@PolyhedronData[pname,"Orientations"]

Polygons

PolyhedronData[pname,"FaceCount"]

PolyhedronFaceTally[p]

Graphics3D/@PolyhedronData[pname,"Polygons"]

Show[%]

Polyhedra

PolyhedronData[pname,"Polyhedra"]

Graphics3D[%]

PolyhedronData[pname,"PolyhedronIndices"]

Region

PolyhedronData[pname,"Region"]

RegionFunction

PolyhedronData[pname,"RegionFunction"]

{RegionPlot3D[ImplicitRegion[PolyhedronData[pname,"RegionFunction"][x,y,z],{x,y,z}]],
Graphics3D[p]}

Collect[#,{x,y,z},RootReduce]&/@PolyhedronInequalities[p,{x,y,z}]

ineq=FullSimplify[%]

ineq/.{x->#,y->#2,z->#3}

{Region@ImplicitRegion[ineq,{x,y,z}],Graphics3D[p]}

SimplePolyhedron

PolyhedronData[pname,"Simple"]

SimplePolyhedronQ[p]

Skeleton

PolyhedronData[pname,"Skeleton"]

gn=PolyhedronData[pname,"Skeleton","Name"]

GraphData[gn]

emb=GraphData[gn,"PolyhedralEmbeddings"]

l={{gn,{0,Union[emb,{pname}]}}}

PropertyReplace[l,"PolyhedralEmbeddings","14.0"]

pname

With[{verts=PolyhedronData[pname,"Vertices"],faces=PolyhedronData[pname,"Faces","List"]},
ToCommonEdges[GraphData[gn],Graph[Range[Length[verts]],UndirectedEdge@@@Union[Sort/@Flatten[Partition[#,2,1,1]&/@faces,1]]]]]//Chop[#,1*^-5]&//N

GraphData[gn,"Graph",{"3D","All"}]

g=PolyhedronGraph[p]

SurfaceArea

PolyhedronData[pname,"SurfaceArea"]

SurfaceArea[p]

Total[Area/@PolyhedronData[pname,"Polygons"]]

SurfaceArea[PolyhedronData[pname,"Region"]]

Uniform

PolyhedronData[pname,"Uniform"]

With[{rules=PolyhedronData[pname,"NotationRules"]},{
UniformPolyhedron[Lookup[rules,"WenningerIndex"]],
UniformPolyhedron[{"Coxeter",Lookup[rules,"CoxeterIndex"]}],
UniformPolyhedron[{"Kaleido",Lookup[rules,"KaleidoIndex"]}],
UniformPolyhedron[{"Uniform",Lookup[rules,"MaederIndex"]}],
UniformPolyhedron[{"Wenninger",Lookup[rules,"WenningerIndex"]}]
}]

SameQ@@%

VertexCount

PolyhedronData[pname,"VertexCount"]

VertexSubsetHulls

subsethulls=PolyhedronData[pname,"VertexSubsetHulls"]

v=PolyhedronData[pname,"Vertices"];

Rule[#,Length[#2]]&@@@subsethulls

Rule[#,Graphics3D[Function[f,ConvexHullRegion[v[[f]]]]/@#2]]&@@@subsethulls

subsethulls2=Flatten[Function[{pn,l},Rule[pn,#]&/@l]@@@subsethulls]

Rule[#,Graphics3D[{{Opacity[.3],{Green,p}},Blue,ConvexHullRegion[v[[#2]]]}]]&@@@subsethulls2

Convex hull

Graphics3D[convexhullreg=ConvexHullRegion[v=PolyhedronData[pname,"Vertices"]]]

v=PolyhedronCoordinates[convexhullreg]

Flatten[(convexhullreg[[2]]/.i_Integer:>v[[i]])/.Thread[PolyhedronData[pname,"Vertices"]->Range[PolyhedronData[pname,"V"]]]]//Union

%===Range@Length@v

PolyhedronData[pname,"ConvexHull","Name"]

Platonic

(h=VertexSubsetHulls[p,"Platonic","Skip"->{}])//Timing

Volume

PolyhedronData[pname,"Volume"]

Volume[p]//FullSimplify

PolyhedronVolume[p]//FullSimplify

Volume[PolyhedronData[pname,"Region"]]//FullSimplify

Volume[ImplicitRegion[Evaluate@PolyhedronData[pname,"RegionFunction"][x,y,z],{x,y,z}]]//FullSimplify

WythoffSymbol

PolyhedronData[pname,"WythoffSymbol"]

Properties: {"OctahedronFiveCompound", 2}

Initialization

<<MathWorld`Polyhedra`

p=PolyhedronData[pname={"OctahedronFiveCompound",2},"Polyhedron"]

AdjacentFaceIndices

adj1=PolyhedronData[pname,"AdjacentFaceIndices"]

adj2=AdjacentFaceIndices[p]

adj1===adj2

Centroid

PolyhedronData[pname,"Centroid"]

Circumsphere

sphere=PolyhedronData[pname,"Circumsphere"]

sphere=Circumsphere[p]

(sphere=MyCircumsphere[p])//Timing

Graphics3D[{{Opacity[.2],Yellow,sphere},p},Boxed->False]

Classes

PolyhedronData[pname,"Classes"]

Compound

PolyhedronData[pname,"Compound"]

CompoundInterior

intname=PolyhedronData[pname,"CompoundInterior","Name"]

PolyhedronData[pname,"CompoundInterior","Scale"]

PolyhedronData[pname,"CompoundInterior","RotationMatrix"]

PolyhedronData[pname,"CompoundInterior"]

Graphics3D[{
AbsoluteThickness[1],PolyhedronData[pname,"Lines"],
Opacity[.8],interior=PolyhedronData[pname,"CompoundInterior","Polyhedron"]},Boxed->False]

MyCircumsphere[interior]//Quiet

Insphere[interior]//Quiet

Midsphere[interior]

Construction

int=RegionIntersection[Sequence@@PolyhedronData[pname,"Polyhedra"],PerformanceGoal->"Quality"]

Graphics3D[int]

Graphics3D[{{Opacity[.2],p},Red,int},Boxed->False]

Union[Chop@int[[1]]]//Length

Exactify

vexact=DeleteDuplicates[RootApproximant[Chop[int[[1]]]]]

Length[vexact]

inthull=ConvexHullRegion[Union@vexact]

v=inthull[[1]]

faces=inthull[[2]]

gname=RecognizeGraph@PolyhedronGraph[inthull]

GraphData[gname,"PolyhedralEmbeddings"]

SimplifyNumericallyDistinct[PolyhedronEdgeLengths[inthull]]//Counts//Quiet

Numerically group

Union[Chop@int[[1]]]//Length

Length[grouped=SplitBy[SortBy[{#,Round[1*^12#]}&/@Chop[int[[1]]],Last],Last][[All,All,1]]]

rules=Flatten[Function[l,Rule[#,Mean[l]]&/@l]/@grouped,1];

newi=ConvexHullRegion[DeleteDuplicates[Chop[int[[1]]]/.rules]]

Midsphere[newi]

RecognizeGraph@PolyhedronGraph@newi

lengths=PolyhedronEdgeLengths[newi]

Divide@@MinMax[%lengths]

Round[10^12lengths]/10^12.//Counts

PolyhedronData["PentakisDodecahedron","EdgeLengths"]

Divide@@%//N

RootReduce[PolyhedronEdgeLengths[PolyhedronData["PentakisDodecahedron","Polyhedron"]]]//Counts

newi[[1]]

newi[[2]]

RootApproximant[((newi[[1]])/(Max[PolyhedronEdgeLengths[newi]])),4]

Graphics3D[{
AbsoluteThickness[1],PolyhedronData[pname,"Lines"],
Opacity[.8],newi},Boxed->False]

Find scale

intname=XXX;

PolyhedronData/@{pname,intname}

xyratio=((Max[Norm/@vexact[[All,;;2]]])/(Max[Norm/@PolyhedronData[intname,"VertexCoordinates"][[All,;;2]]]))//RootReduce//FullSimplify//Quiet

zratio=((Max[vexact[[All,3]]])/(Max[PolyhedronData[intname,"VertexCoordinates"][[All,3]]]))//RootReduce//FullSimplify

{xyratio,xyratio,zratio}

Concave

PolyhedronData[pname,"Concave"]

Convex

PolyhedronData[pname,"Convex"]

ConvexPolyhedronQ[p]

ConvexHull

convexhullname=PolyhedronData[pname,"ConvexHull","Name"]

PolyhedronData[pname,"ConvexHull","Scale"]

PolyhedronData[pname,"ConvexHull","RotationMatrix"]

Graphics3D[convexhull=PolyhedronData[pname,"ConvexHull","Polyhedron"]]

{
Graphics3D[{Red,Opacity[.5],p}],
Graphics3D[{Blue,Opacity[.5],convexhull}]
}

Show[%]

Construct using ConvexHullRegion

Graphics3D[convexhullreg=ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]

v=PolyhedronCoordinates[convexhullreg]

Sort[(convexhullreg[[2]]/.i_Integer:>v[[i]])/.Thread[PolyhedronData[pname,"Vertices"]->Range[PolyhedronData[pname,"V"]]]]

Find scale

SimplifyNumericallyDistinct[PolyhedronEdgeLengths[convexhullreg]]//Tally//FullSimplify

((Max[Norm/@p[[1]]])/(Max[Norm/@PolyhedronData[convexhullname,"Polyhedron"][[1]]]))//FullSimplify//Quiet

Find rotation matrix

Graphics3D[{FaceForm[Green,Red],basesolid=PolyhedronData[convexhullname,"Polyhedron"],MapIndexed[Text[#2[[1]],#,Background->White]&,basev=basesolid[[1]]]}]

rot=RotationMatrix[{Mean[basev[[{11,12}]]],{0,0,1}}]//FullSimplify

{Graphics3D[{Polyhedron[newv=rot.#&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

ArcTan@@(Most@Mean[newv[[{7,29}]]])//FullSimplify

rot2=RotationMatrix[Pi/2+2Pi/5,{0,0,1}].rot//FullSimplify

{Graphics3D[{Polyhedron[(rot2.#)&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

ConvexHullOf

hullof=DeleteCases[Select[PolyhedronData[All],PolyhedronData[#,"ConvexHullName"]===pname&],pname]

GraphicsGrid[Partition[Graphics3D[{
{Green,Opacity[.7],PolyhedronData[#,"Polyhedron"]},
{Blue,Opacity[.2],PolyhedronData[#,"ConvexHull","Polyhedron"]}},Boxed->False,PlotLabel->Style[PolyhedronData[#,"Name"],Directive[14,Black,Italic,FontFamily->"Times"]]]&/@hullof,UpTo[3]],Dividers->All,ImageSize->800]

DehnInvariant

PolyhedronData[pname,"DehnInvariant"]

(dehn=DehnInvariant[p,Debug->True]//FullSimplify)//Timing

ToConwayBasis[dehn]

Complement[Select[PolyhedronData[All],PolyhedronData[#,"DehnInvariant"]==dehn&&PolyhedronData[#,"Volume"]==vol&],{pname}]

DihedralAngles

(dih1=PolyhedronData[pname,"DihedralAngles"])//Tally

(dih2=SimplifyNumericallyDistinct[DihedralAngles[p]])//Tally

dih1===dih2

Dual

pname

dname=PolyhedronData[pname,"Dual","Name"]

PolyhedronData[pname,"Dual","Scale"]

midrs={PolyhedronData[pname,"Midradius"],PolyhedronData[dname,"Midradius"]}

Divide@@midrs//FullSimplify

GraphicsRow[With[{
s={Yellow,PolyhedronData[pname,"Midsphere"]},
style=Directive[Black,Italic,FontFamily->"Times",14]
},
{
Graphics3D[{s,Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},Boxed->False,PlotLabel->TextCell[Style[PolyhedronData[pname,"Name"],style],PageWidth->200,TextAlignment->Center]],
Graphics3D[{s,Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},Boxed->False,PlotLabel->Style[PolyhedronData[dname,"Name"],style]],
Graphics3D[{
{Green,Opacity[.5],PolyhedronData[pname,"Polyhedron"]},
{Red,Opacity[.5],PolyhedronData[pname,"Dual","Polyhedron"]},
s
},Boxed->False,PlotLabel->Style["compound with midsphere",style]],
Graphics3D[{
PolyhedronData[pname,"Polyhedron"],
PolyhedronData[pname,"Dual","Polyhedron"]
},Boxed->False,PlotLabel->Style["compound",style]]
}],Alignment->Top,ImageSize->800]

EdgeCount

PolyhedronData[pname,"EdgeCount"]

EdgeLengths

Tally[lens=SimplifyNumericallyDistinct[PolyhedronEdgeLengths[p],"Simplification"->RootReduce]//FullSimplify]//Timing

PolyhedronData[pname,"EdgeLengths"]

PolyhedronData[pname,"Lines"]/.Line[l_]:>EuclideanDistance@@l//FullSimplify//Union//Quiet

(distinctlens=Mean/@Split[Sort[lens],Abs[#1-#2]<1.*^-10&])//N//Quiet

v=p[[1]];

colors=With[{n=Length[distinctlens]},Table[Hue[i/n],{i,0,n-1}]]

Graphics3D[{Thick,Sequence@@Nearest[Thread[distinctlens->colors],EuclideanDistance@@v[[#]]],Line[v[[#]]]}&/@PolyhedronEdges[p],Boxed->False]//Quiet

FaceCount

PolyhedronData[pname,"FaceCount"]

GeneralizedDiameter

PolyhedronData[pname,"GeneralizedDiameter"]

GeneralizedDiameter[p]//FullSimplify//Quiet

Hull

hullname=PolyhedronData[pname,"Hull","Name"]

PolyhedronData[pname,"Hull","Scale"]

((Max[Norm/@p[[1]]])/(Max[Norm/@PolyhedronData[hullname,"Polyhedron"][[1]]]))//FullSimplify//Quiet

PolyhedronData[pname,"Hull"]

Max[Norm/@PolyhedronData[pname,"Hull","Polyhedron"][[1]]]

Max[Norm/@p[[1]]]

{Graphics3D[{Opacity[.5],Red,p}],Graphics3D[{Opacity[.5],Blue,PolyhedronData[pname,"Hull"][[1]]}]}

Show[%]

Find rotation matrix

Graphics3D[{FaceForm[Green,Red],basesolid=PolyhedronData[hullname,"Polyhedron"],MapIndexed[Text[#2[[1]],#,Background->White]&,basev=basesolid[[1]]]}]

rot=RotationMatrix[{Mean[basev[[{11,12}]]],{0,0,1}}]//FullSimplify

{Graphics3D[{Polyhedron[newv=rot.#&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

ArcTan@@(Most@Mean[newv[[{7,29}]]])//FullSimplify

rot2=RotationMatrix[Pi/2+2Pi/5,{0,0,1}].rot//FullSimplify

{Graphics3D[{Polyhedron[(rot2.#)&/@basesolid[[1]],basesolid[[2]]],MapIndexed[Text[#2[[1]],#,Background->White]&,basesolid[[1]]]}],
Graphics3D[ConvexHullRegion[PolyhedronData[pname,"Vertices"]]]}

HullOf

Select[PolyhedronData[All],PolyhedronData[#,"HullName"]===pname&]

Select[PolyhedronData[All],PolyhedronData[#,"HullName"]===hullname&]

InertiaTensor

PolyhedronData[pname,"InertiaTensor"]

(i=((MomentOfInertia[p,{0,0,0}])/vol))//Timing

Map[ToAlgebraicRoot,i,{2}]

PolyhedronInertiaTensor[p]//Timing

Insphere

PolyhedronData[pname,"Insphere"]

Insphere[p]

sphere=MyInsphere[p]

Graphics3D[{{Opacity[.2],p},{Red,sphere}},Boxed->False]

MeanCylindricalRadius

PolyhedronData[pname,"MeanCylindricalRadius"]

MeanSquareCylindricalRadius

PolyhedronData[pname,"MeanSquareCylindricalRadius"]

MeanSphericalRadius

PolyhedronData[pname,"MeanSphericalRadius"]

MeanSquareSphericalRadius

PolyhedronData[pname,"MeanSquareSphericalRadius"]

Midsphere

sphere=PolyhedronData[pname,"Midsphere"]

(sphere=Midsphere[p])//Timing

(sphere=Midsphere[p,Method->"PointLineDistance"])//Timing

Graphics3D[{{Opacity[.5],Yellow,p},{Red,sphere}},Boxed->False]

Net

NotationRules

PolyhedronData[pname,"NotationRules"]

Orientations

PolyhedronData[pname,"Orientations"]

PolyhedronData[pname,"DefaultOrientation"]

Show[PolyhedronData[{pname,#}],Boxed->False]&/@PolyhedronData[pname,"Orientations"]

Polygons

PolyhedronData[pname,"FaceCount"]

PolyhedronFaceTally[p]

Graphics3D/@PolyhedronData[pname,"Polygons"]

Show[%]

Polyhedra

PolyhedronData[pname,"Polyhedra"]

Graphics3D[%]

PolyhedronData[pname,"PolyhedronIndices"]

Region

PolyhedronData[pname,"Region"]

RegionFunction

PolyhedronData[pname,"RegionFunction"]

{RegionPlot3D[ImplicitRegion[PolyhedronData[pname,"RegionFunction"][x,y,z],{x,y,z}]],
Graphics3D[p]}

Collect[#,{x,y,z},RootReduce]&/@PolyhedronInequalities[p,{x,y,z}]

ineq=FullSimplify[%]

ineq/.{x->#,y->#2,z->#3}

{Region@ImplicitRegion[ineq,{x,y,z}],Graphics3D[p]}

SimplePolyhedron

PolyhedronData[pname,"Simple"]

SimplePolyhedronQ[p]

Skeleton

PolyhedronData[pname,"Skeleton"]

gn=PolyhedronData[pname,"Skeleton","Name"]

GraphData[gn]

emb=GraphData[gn,"PolyhedralEmbeddings"]

GraphData[gn,"Graph",{"3D","All"}]

g=PolyhedronGraph[p]

SurfaceArea

PolyhedronData[pname,"SurfaceArea"]

SurfaceArea[p]

Total[Area/@PolyhedronData[pname,"Polygons"]]

SurfaceArea[PolyhedronData[pname,"Region"]]

Uniform

PolyhedronData[pname,"Uniform"]

VertexCount

PolyhedronData[pname,"VertexCount"]

VertexSubsetHulls

subsethulls=PolyhedronData[pname,"VertexSubsetHulls"]

v=PolyhedronData[pname,"Vertices"];

Rule[#,Length[#2]]&@@@subsethulls

Rule[#,Graphics3D[Function[f,ConvexHullRegion[v[[f]]]]/@#2]]&@@@subsethulls

subsethulls2=Flatten[Function[{pn,l},Rule[pn,#]&/@l]@@@subsethulls]

Rule[#,Graphics3D[{{Opacity[.3],{Green,p}},Blue,ConvexHullRegion[v[[#2]]]}]]&@@@subsethulls2

Convex hull

Graphics3D[convexhullreg=ConvexHullRegion[v=PolyhedronData[pname,"Vertices"]]]

v=PolyhedronCoordinates[convexhullreg]

Flatten[(convexhullreg[[2]]/.i_Integer:>v[[i]])/.Thread[PolyhedronData[pname,"Vertices"]->Range[PolyhedronData[pname,"V"]]]]//Union

%===Range@Length@v

PolyhedronData[pname,"ConvexHull","Name"]

Platonic

(h=VertexSubsetHulls[p,"Platonic","Skip"->{}])//Timing

Volume

PolyhedronData[pname,"Volume"]

Volume[p]//FullSimplify

PolyhedronVolume[p]//FullSimplify

Volume[PolyhedronData[pname,"Region"]]//FullSimplify

Volume[ImplicitRegion[Evaluate@PolyhedronData[pname,"RegionFunction"][x,y,z],{x,y,z}]]//FullSimplify

WythoffSymbol

PolyhedronData[pname,"WythoffSymbol"]

Construction

<<MathWorld`Polyhedra`

{"OctahedronFiveCompound", 1} from dual

poly=PolyhedronData[{"CubeFiveCompound",1},"Polyhedra"]

duals=PlatonicDual/@poly

Graphics3D[duals]

Graphics3D/@Transpose[{poly,duals}]

Show[%]

vduals=duals[[All,1]]//RootReduce

Length[Flatten[vduals,1]]

Length[v=DeleteDuplicates[Flatten[vduals,1]]]

faces=RootReduce[(Function[f,#[[1]][[f]]]/@#[[2]])&/@duals]/.Thread[v->Range@Length@v]//Quiet

Flatten[faces,1]

Graphics3D[compound=Polyhedron[FullSimplify@v,Flatten[faces,1]]]

{"OctahedronFiveCompound", 1}  from VertexSubsetCompound["Icosidodecahedron", "Octahedron"]

compound=VertexSubsetCompound["Icosidodecahedron","Octahedron"]

Graphics3D[compound]

(hulls=VertexSubsetHulls[compound,"Platonic"])//Timing

Rule[#,Length[#2]]&@@@hulls

{"OctahedronFiveCompoundHull", 1}

v=PolyhedronData["Octahedron5Compound","VertexCoordinates"];

e=Flatten[Normal[PolyhedronData["Octahedron5Compound","Edges"]]];

e[[1]]

Length[e]

Length[pts=Union[Flatten[Intersection3D@@@Subsets[e,{2}]]]]//Quiet//Timing

Graphics3D[{PolyhedronData["Octahedron5Compound","Faces"],PointSize[.02],Point[pts[[All,1]]]},Boxed->False]

l=pts[[All,1]];

Export["expr.m",l]

ByteCount[l=Get["expr.m"]]

pts2=RootReduce[l];//Timing

Length[vs=Split[SortBy[{RootReduce[Norm[#]],#}&/@pts2,N],First[#1]==First[#2]&]]//Timing

Length/@vs

ds=ToRadicals[#[[1,1]]&/@vs]//FullSimplify

N[%]

Graphics3D[{PolyhedronData["Octahedron5Compound","Faces"],PointSize[.03],
Point[vs[[1]][[All,2]]],
Red,Point[vs[[2]][[All,2]]],
Green,Point[vs[[3]][[All,2]]]
}//N,Boxed->False]

chs=ConvexHull3D[#[[All,2]]]&/@vs;//Timing

chs

GraphicsGrid[{Graphics3D[#,Boxed->False]&/@chs},Spacings->-70,ImageSize->400]

ch12=ConvexHull3D[Join@@(#[[All,2]]&/@Take[vs,2])]

PolyhedronVertices[ch12]//Length

SortBy[FullSimplify[PolyhedronEdgeLengths[ch12]],N]

N[%]

PolyhedronData[32]

Graphics3D[{ch12,PointSize[.03],
Point[vs[[1]][[All,2]]],
Red,Point[vs[[2]][[All,2]]]}]

Graphics3D[{ch12,PointSize[.03],
MapIndexed[Text[#2[[1]],#1,Background->White]&,Union[vs[[1]][[All,2]]]],
Red,MapIndexed[Text[#2[[1]],#1,Background->White]&,Union[vs[[2]][[All,2]]]]}]

Pentagon-apex distance

RootReduce[Distance3D[Polygon[Union[vs[[2]][[All,2]]][[{9,17,11,4,3}]]],Point[Union[vs[[1]][[All,2]]][[11]]]]]

Normalized

RootReduce[%38/Norm[Subtract@@Union[vs[[2]][[All,2]]][[{9,17}]]]]

Graphics3D[Cumulate[Flatten[Normal[PolyhedronData["Dodecahedron","Faces"]]],Root[1-25 ((#1)^2)+5 ((#1)^4)&,3]]]

{r1,r2,r3}=Union[vs[[#]][[All,2]]]&/@{1,2,3};

r3

Graphics3D[pp=Orient[Flatten[Function[f,Outer[Polygon[{f,#1,#2}]&,Nearest[r1,f,2],Nearest[r2,f,2],1]]/@Take[r3,All]]]]

Graphics3D[{FaceForm[Red,Blue],pp}]

Volume[Orient[pp]]

ToRadicals[RootReduce[PolyhedronSymmetricVolume[pp]]]//FullSimplify

SortBy[FullSimplify[PolyhedronEdgeLengths[pp]],N]

{"OctahedronFiveCompoundHull", 1} pieces

<<Platonic`;
<<DiscreteMath`Combinatorica`;
<<SolidGeometry`;
<<Simplify`
Off[$MaxExtraPrecision::"meprec"];

FaceIntersections[poly_]:=Module[{pairs=KSubsets[Take[#,3]&/@First/@poly,2]},
DeleteCases[Intersection3D@@@Map[Plane,pairs,{2}],{}]
]

Timing[Length[f=FaceIntersections[Flatten[Polyhedron[Octahedron5Compound]]]]]

Timing[Length[lines=Map[ToExact,f,{3}]]]

Timing[Length[points=Intersection3D@@@KSubsets[lines,2]]]

Timing[Length[p=First/@Union[Select[DeleteCases[points,{}],#[[1]].#[[1]]≤5.&&#[[1,2]]<0&]]]]

Length[p2=Select[p,#.#<3&]]//Timing

Show[Graphics3D[{Polyhedron[Octahedron5Compound],
PointSize[.02],
Point/@p2//N,
MapIndexed[Text[#2[[1]],#1+{0,0,.05},Background->White]&,p2//N]
}],Boxed->False,ViewPoint->{0,-2,0},PlotRange->All]

<<Simplify`;
Off[$MaxExtraPrecision::"meprec"];

q1=Map[ToExact,p2[[{80,690,533}]],{2}]

q1={{0,(1/2) (-1-(Sqrt[5])),0},{-(Sqrt[(1/5) (5-2 (Sqrt[5]))]),-1,(Sqrt[(1/2)-(1/(2 (Sqrt[5])))])},{(Sqrt[(1/10)+(1/(10 (Sqrt[5])))]),(1/10) (-5-3 (Sqrt[5])),(Sqrt[(1/10)-(1/(10 (Sqrt[5])))])}};

r1=Map[ToExact,Polygon2D[q1],{3}][[1]]

r1={{0,0},{(Sqrt[(3/4)-((Sqrt[5])/4)]),(Sqrt[(9/4)-((3 (Sqrt[5]))/4)])},{(Sqrt[(2/5)]),0}};

Show[Graphics[{net=ClosedLine/@{
rr1={#[[1]],-#[[2]]}&/@(RotationMatrix[Pi/2].#&/@r1),
{-#[[1]],#[[2]]}&/@rr1,
rr2=RotationMatrix[3Pi/2-ArcTan@@(rr1[[2]]-rr1[[1]])].#&/@rr1,
{-#[[1]],#[[2]]}&/@rr2
}}],AspectRatio->Automatic,
PlotRange->All]

net2=Map[ToExact,Flatten[net],{3}];

v=Union[Flatten[First/@net2,1]];

Drop[First[#],-1]&/@net2/.Thread[v->Range[Length[v]]]

v//InputForm

<<Platonic`

Show[Graphics[Net[Octahedron5Compound]],AspectRatio->Automatic]

Show[Graphics[NetDiagram[Octahedron5Compound]],AspectRatio->Automatic]

s=FullSimplify/@NetEdgeLengths[Octahedron5Compound]

sides=Sort[Union[s],Less]

sides//N

FullSimplify[Plus@@sides]

lengths=Sort[Transpose[{s/.Thread[sides->Range[Length[sides]]],NetEdges[Octahedron5Compound]}]]

NetSurfaceArea[Octahedron5Compound]//FullSimplify

N[%]

PolyhedronEdgeLengths[Polyhedron[Octahedron5Compound]]//N

{"OctahedronFiveCompound", 2} by adding base octahedron to {"OctahedronFourCompound", 1}: octahedron rotated by 1/6 of a turn about the line joining the centroids of opposite faces

Graphics3D[PolyhedronRotationCompound[PolyhedronData["Octahedron","Polyhedron"],"Face","AdditionalSolid"->PolyhedronData["Octahedron","Polyhedron"]]]

{"OctahedronFiveCompound", 2} from dual

poly=PolyhedronData[{"CubeFiveCompound",2},"Polyhedra"]

duals=PlatonicDual/@poly

Graphics3D[duals]

Graphics3D/@Transpose[{poly,duals}]

Show[%]

vduals=duals[[All,1]]//RootReduce

Length[Flatten[vduals,1]]

Length[v=DeleteDuplicates[Flatten[vduals,1]]]

faces=RootReduce[(Function[f,#[[1]][[f]]]/@#[[2]])&/@duals]/.Thread[v->Range@Length@v]//Quiet

Flatten[faces,1]

Graphics3D[compound=Polyhedron[FullSimplify@v,Flatten[faces,1]]]

PolyhedronData

PolyhedronDataString

<<MathWorld`Polyhedra`

file=OpenWrite["~/5compound.m"]

WriteString[file,PolyhedronDataString[compound,
"StandardName"->{"OctahedronFiveCompound",2},
"AlternateStandardNames"->{},
"Name"->"second octahedron 5\[Hyphen]compound",
"Information"->"Octahedron5-Compound",
"Classes"->{"Compound"}
]]

Close[file]