Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 31310

Euclidean, hyperbolic, discrete, convex, coarse geometry, metric spaces, comparisons in Riemannian geometry, symmetric spaces.

0 votes

Most dispersed set of points in a disk?

Maybe not an exact answer, but some thoughts to get a foot in the door: no three points must be collinear, because otherwise a triangle with area $0$ would exist and thus every set of points in ge …
Manfred Weis's user avatar
  • 13.2k
0 votes

Most dispersed set of points in a disk?

A more practical heuristic for generating dispersed point sets inside a compact region $\Omega$, that also generates to higher dimensions is the following, which I would like to call the stay away fr …
Manfred Weis's user avatar
  • 13.2k
2 votes
0 answers
104 views

Area of an intersection of three ellipses

Let $\Delta := (A,B,C)$ be a triangle that is defined by three points in the Euclidean plane that are not collinear. Let further $E_{(A,B),\,C},\,E_{(C,A),\,B},\,E_{(B,A),\,B}$ be the set of ellipses …
Manfred Weis's user avatar
  • 13.2k
6 votes

What shapes can be gears?

if you look for non-circular gear you at least find the wiki article that also addresses the mathematics; there are also links to publication on the subject.
Manfred Weis's user avatar
  • 13.2k
1 vote
2 answers
128 views

An optimality condition for the corners of convex polytopes?

Let $H,H'\subset\mathbb{R}^m$ be two hyperplanes with unit normal-vector, and let $P\subset\mathbb{R^m}$ be a convex polytope (defined via its corners $v_0, ... , v_n$, where $n\ge m$). Let's furth …
Manfred Weis's user avatar
  • 13.2k
0 votes

An optimality condition for the corners of convex polytopes?

It just occured to me that the question can be answered in the affirmative way for the following reasons: the order relation doesn't change if the distance sum is divided by some positive constant …
Manfred Weis's user avatar
  • 13.2k
5 votes

How can you compute the maximum volume of an envelope(used to enclose a letter)?

As the envelope is made of paper, a mathematical model of its deformation would be an isometric coordinate transformation and thus must have zero Gauss curvature almost everywhere; that restriction is …
Manfred Weis's user avatar
  • 13.2k
2 votes
0 answers
36 views

Is there a "last mile" criterion for a generalization of planar convex hulls to symmetric we...

This question is motivated by an almost successful attempt to define planar convex hulls of a finite set of isolated points only via subset sums of the distances between point-pairs; the advantage of …
Manfred Weis's user avatar
  • 13.2k
1 vote
0 answers
27 views

Finding most Representative Sample in "Pair Statistics"

By "Pair Statistics" I understand statics that are based on values $\varphi:\mathcal{P}\times\mathcal{P}\ni(p,q)\mapsto y\in\mathbb{R}$ that can be observed for every pair $(p,q)$ of individuals of a …
Manfred Weis's user avatar
  • 13.2k
1 vote
1 answer
38 views

Is this relation between planar convex hulls and heaviest cliques true?

If $P$ is a set of $n$ points in the euclidean plane whose convex hull $\operatorname{CH}(P)$ has $h$ corners, and $Q\subset P$ has $m\le\lfloor\frac{h}{2}\rfloor$ points and maximal sum of pairwise d …
Manfred Weis's user avatar
  • 13.2k
3 votes
1 answer
188 views

Deflating a tetrahedron to a $K_4$ graph with equal changes to sidelengths

Let $A,B,C,D$ be the corners of a tetrahedron with positive volume and distinct sidelengths. Is there a positive $x$ and a planar straight-line embedding of a $K_4$ graph with distinct vertices $A’,B’ …
Manfred Weis's user avatar
  • 13.2k
1 vote

closest equidistant point to N points in M dimensions

An algorithm that works at least for dimensions $2$ and $3$ is: calculate a spanning tree of the $n$ points calculate the bisector planes of the spanning tree's edges the sought poiint is in the inte …
Manfred Weis's user avatar
  • 13.2k
1 vote

Characterization of greedy TSPs?

A simple "a posteriori" criterion is that on the optimal tour the distances to the tour-neighbors is smaller than that to any of the other vertices. Convexity alone doesn't suffice as the example of e …
Manfred Weis's user avatar
  • 13.2k
3 votes

Equitably distributed curve on a sphere

to me the best possible solution seems to be the sequence of closed Hilbert curves on the Cubed Sphere; that curve consists of six ordinary Hilbert Curves, one for each face of a cube, which, when app …
Manfred Weis's user avatar
  • 13.2k
1 vote
0 answers
211 views

Quadrilaterals from a Unit Stick

This question could be seen as a coordinate-free variant of Sylvester's Four Point Problem (cf e.g. http://mathworld.wolfram.com/SylvestersFour-PointProblem.html): Suppose one are given an inifinit …
Manfred Weis's user avatar
  • 13.2k

15 30 50 per page