Tagged Questions
1
vote
1answer
41 views
Set boundary preserved by an infinite union
Suppose I have a subset $U\subset\mathbb R^2$ and a real number $r>1$ with the following properties:
$U$ is compact;
$U\subset rU$ (self-similarity);
$0\in U$;
there exists an open set $H\subset ...
1
vote
1answer
257 views
How to plot N points on the surface of a D-dimensional sphere roughly equidistant apart?
Let's say I have a D-dimensional sphere with a radius R. I want to plot N number of points evenly distributed (equidistant apart from each other) on the surface of the sphere. It doesn't matter where ...
-1
votes
1answer
103 views
Practical implications of a vector space being a topological vector space
I have a space $V$ and I lately discovered that it's a topological vector space. What are the practical implications of that?
0
votes
0answers
54 views
Finding point distribution by eigen vectors
First of all I want to tell that my mathematics is poor, so I can’t use correct terms. Sorry for that.
I have a point data set. This data represents some cylindrical objects surfaces (not exactly ...
0
votes
2answers
138 views
Vector Analysis & Linear Algebra
I'm given a positive number, a unit vector $u \in \mathbb{R} ^n $ and a sequence of vectors $ \{ b_k \} _{ k \geq 1} $ such that $|b_k - ku| \leq d $ for every $ k=1,2,...$.
This obviously implies $ ...
0
votes
0answers
79 views
Can 2 parallel lines be discriminated as 'away', 'beside' with respect to 3rd parallel line?
I have nearly parallel several 3D line segments. some line segments locate (blue line) beside to a spefic line segment (black line) and some other (red line) locate away from that line segment. i want ...
0
votes
0answers
32 views
A subset that can be scaled to be the whole space, or that can contain a scaled version of the whole space
The following is from Mariano's comments on my earlier question
In a topological vector space, why is the following true:
if a neighborhood U of zero contains a scaled copy of the whole space,
...
1
vote
1answer
111 views
How to get a projected 3d line segment, lie on another 3d line parallel to that line segment.
I have a 3D line segment and another 3D position which locate slightly away from the line segment. I want to get the projected line segment (3D) which lies on imaginary 3D line which passes through ...
3
votes
0answers
82 views
Self-absorbing subsets in a vector space
From planetmath
Let $V$ be a vector space over a field $F$ equipped with a
non-discrete valuation $|\cdot|:F\to \mathbb{R}$ . Let $A$ and $B$ be two
subsets of $V$. Then $A$ is said to absorb ...
