Wolfram Mathematica

« first day (1179 days earlier) ← previous day next day → last day (3295 days later) »

11:42 AM

Q: Meaning of down vote for down voting question

Please see this question. I down-voted this answer as given the question title and the first line I sincerely believe the answer provided was not correct. I provided my rationale in an answer. I note this led to a penalty: I am trying to understand the reason either I can correct my error in...

5 hours later…

Szabolcs

4:17 PM

I saw this question about tiling the sphere with hexagons and I'm curious if this is possible at all. Somehow I don't really believe it's possible.

Q: Create hexagonal mesh on 3D Parametric Plot and 3D spheres?

I am looking to put a cool geometric mesh on this object. I came across this question that explained how to put a hexagonal mesh on a parametric equation but I have a series of geometric objects of which use the Graphics3D sphere function along with the parametric equation function, here is the c...

graphics3d mesh

3 hours later…

Michael E2

7:03 PM

@Szabolcs A surface tiled entirely with hexagon has an Euler characteristic of zero. A sphere has characteristic 2. So you're right, it's not possible. You can do it with 12 pentagons plus any number of hexagons.

1 hour later…

Michael E2

8:18 PM

@UnitedKingdom Code dump:

g = Show[
   ParametricPlot3D[{Cos[t], Sin[t], z},
    {t, 0, Pi/4}, {z, -Sin[t], Sin[t]},
    Mesh -> None],
   ParametricPlot3D[{Cos[t], Sin[t], #} & /@ {-Sin[t], Sin[t]},
    {t, 0, Pi/4},
    PlotStyle -> Thin]
   ];
Graphics3D[
 With[{g = First[g]},
  GeometricTransformation[
   {g,
    GeometricTransformation[g,
     Table[RotationTransform[t, {0, 0, 1}], {t, 0, 3 Pi/2, Pi/2}]],
    GeometricTransformation[g,
     Table[RotationTransform[
        t, {0, 0, 1}].ScalingTransform[{1, -1, 1}, {1, 0, 0}], {t, 0,

3 hours later…