Mathematica routines for sphere packings
Mathematica Sphere Packing Code
This file gives descriptions of functions appearing in
a Mathematica package designed to assist in the exploration
of packings in three dimensions. Detailed descriptions of most
of these functions can be found in Sphere Packings I.
The source code is available.
Sean McLaughlin has also implemented many of these functions in
Maple.
- zeta, pt, doct
- Various constants
- chi
- A polynomial in six variables giving the orientation of a simplex
along the fourth, fifth and sixth edges
- eta
- eta[x,y,z] is the circumradius of a triangle with edges x,y,z.
- volR[a,b,c]
- the volume of the Rogers simplex R[a,b,c]
- solR[a,b,c]
- the solid angle of the Rogers simplex R[a,b,c]
- dihR[a,b,c]
- the dihedral angle of the Rogers simplex R[a,b,c]
- vorR[a,b,c]
- the voronoi score of the Rogers simplex R[a,b,c]
- denR[a,b,c]
- the packing density of the Rogers simplex R[a,b,c]
- tauR[a,b,c]
- the amount squandered by the Rogers simplex R[a,b,c]
- TRUNC
- 1.255
- Dihedral[y1,...,y6]
- The dihedral angle of a simplex with edges y1,...,y6.
- Dihedral2[y1,...,y6]
- The dihedral angle along the second edge
of a simplex with edges y1,...,y6.
- Dihedral3[y1,...,y6]
- The dihedral angle along the third edge
of a simplex with edges y1,...,y6.
- Chi[y1,...,y6]
- The function Chi along the top
face of a simplex with edges y1,...,y6
- tauAnalytic[y1,...,y6]
- What the simplex S(y1,...,y6) squanders under the analytic Voronoi
function.
- tau[y1,...,y6]
- What the simplex S(y1,...,y6) squanders under compression.
- VorAnalytic[y1,..,y6]
- The analytic voronoi function at the simplex S(y1,...,y6)
- Delta[y1,...,y6]
- The function delta expressed in terms of edge lengths.
- U[x1,x2,x6]
- The function U expressed in terms of squares of edge lengths.
- Rho[y1,...,y6]
- The function rho expressed in terms of edge lengths
- Rad[y1,...,y6]
- The circumradius of a simplex S(y1,...,y6)
- aSolid[y1,...,y6]
- The function a(y1,...,y6) appearing in the definition of solid angles
- Gamma[y1,...,y6]
- The compression of the simplex S(y1,...,y6)
- Solid[y1,...,y6]
- The solid angle of a simplex S(y1,...,y6)
- Density[x]
- The packing density corresponding to a score of x
- Norm[x]
- The length squared of a vector x
- Norm[x,y]
- The distance squared from x to y
- Distance[x,y]
- The Euclidean distance between vectors x and y
- FarFrom[v1,{u,v}]
- This function returns vector u or v depending on which has the
greatest distance from v1.
- ExtremePoint[{v1,v2,v3}]
- The circumcenter of the simplex with vertices 0,v1,v2,v3.
- Vertex[{v1,dist1},{v2,dist2},{v3,dist3}]
- This function returns a pairs of vectors {u1,u2}, where u1 and u2
are the two vectors at distance dist1 from vector 1, dist2 from vector2,
and dist3 from vector3.
- SimplexCoordinates[y1,...,y6]
- This function returns {v1,v2,v3}, where 0,v1,v2,v3 are the
coordinate vectors of the four vertices of a simplex with
edges y1,...,y6.
- Enclosed[y1,...,y6,z1,z2,z3]
- The function \\Cal E from Sphere Packings papers
- NullVector
- The vector {0,0,0}
- Keep[x]
- Place the definition of x in the file keep.m
- Fix[x]
- Edit the definition of x
- $SpherePrecision
- The working precision for calculations in the package
- Ns[x]
- Evaluate x to the precision $SpherePrecision
This page is available for historical purposes only. It is a copy
from www.math.lsa.umich.edu/~hales/countdown. It has not been
maintained since 1998.