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 126667

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

29 votes
Accepted

How does one find the "loneliest person on the planet"?

The paper Vaidya, Pravin M., An $O(n \log n)$ algorithm for the all-nearest-neighbors problem, Discrete Comput. Geom. 4, No. 2, 101-115 (1989), ZBL0663.68058 gives an $O(n \log n)$ algorithm for the " …
The Amplitwist's user avatar
1 vote
Accepted

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

Yes, this is true. The main point is that the "first thing that goes wrong" cannot be two vertices coming together. Let $a_0$, $b_0$, $c_0$, $d_0$, $e_0$, $f_0$ denote the edge lengths of the original …
Reid Barton's user avatar
  • 25.2k
8 votes

How to compute the average distance till intersection within a triangle in $\mathbb{R}^2$?

If you call the random variable you described X, then it's much easier to compute the expected value of X2. Indeed, for any point P inside triangle ABC, the expected value of X2 where X is the length …
Reid Barton's user avatar
  • 25.2k
18 votes

Is it possible to capture a sphere in a knot?

The regular dodecahedron is not a local minimum for total edge length either. Consider the five vertices Vi, i = 1, ..., 5 of a face together with the "center" C of the face. The spherical triangle …
Reid Barton's user avatar
  • 25.2k
5 votes

Feasibility of a list of prescribed distances in R^3

Embedded in Anton's answer are the following two aspects of the problem: You first need to decide (or be given) the combinatorial structure of the graph you want to embed, i.e., assign the n distanc …
Reid Barton's user avatar
  • 25.2k
13 votes

Upper bound on the area of a midpoint pentagon?

I used qepcad to compute that the intersection of the set of possible area ratios with the interval [1/2, 3/4] is (1/2, 3/4). Since the set of possible area ratios is the image of a connected space u …
Reid Barton's user avatar
  • 25.2k
24 votes

Algorithm for finding the volume of a convex polytope

I think this problem is hard--the known algorithms are both slow and nontrivial to implement. See Exact Volume Computation for Polytopes for a survey. An interesting feature is that there are variou …
Reid Barton's user avatar
  • 25.2k