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1 vote
1 answer
264 views

Could somebody suggest a way to determine if a parallelogram contains another parallelogram?

I thought of one way to do this. Using the algorithm which determines if a point is inside a parallelogram, one can determine if the polygon contains the point within $2N$ steps ($N=2$ for ...
syk's user avatar
  • 19
0 votes
1 answer
1k views

Fast way to generate random points in 2D according to a density function

I'm looking for a fast way to generate random points in 2D according to a given 2D density function. For instance something like this: Right now I'm using a modified version of "Poisson disc&...
shoosh's user avatar
  • 121
4 votes
2 answers
213 views

Algorithm for reporting all triangles with unique interior point

What is known about the complexity of and/or practical algorithms for reporting all triplets of points from finite set of at least four points of which no three are collinear in the Euclidean plane, ...
Manfred Weis's user avatar
  • 13.2k
0 votes
3 answers
115 views

Calculating radii allowing for circular placement of polygonal linkage's joints

Given a planar polygonal linkage defined by a sequence of $n$ hinge joints $(j_0,\,\cdots,\,j_{n-1},j_n = j_0)$ with links of fixed lengths $\lbrace\|j_{k+1}-j_k\|=d_k\ |\ 0\le k\lt n\rbrace$ between ...
Manfred Weis's user avatar
  • 13.2k
3 votes
1 answer
140 views

Find the smallest circumference of a figure containing n squares [closed]

So there's a figure which contains n squares of 1 x 1, and I have to find the smallest circumference possible. I don't know if there's an algorithm behind this, I've been stuck on this for two hours ...
Jimmy's user avatar
  • 31
2 votes
1 answer
69 views

Maximal opening angle of a polygon from a point [closed]

I'm looking for an algorithm that given a 2D convex polygon and point outside it, returns the two points of the polygon which are the two extremities of the polygon when viewed from that point. One ...
shoosh's user avatar
  • 121
4 votes
2 answers
4k views

Curves similarity metric [closed]

I am working on an optical character recognition algorithm that takes vector data (i.e. polylines) as input rather than raster picture. E.g., we have N polyline samples, and when certain polyline is ...
Oleg Andriyanov's user avatar
3 votes
1 answer
288 views

Generalization of notion of convexity

I am searching for the correct term for the following, if it exists. A set $X\subset \mathbb{R}^2$ is called $r$-convex if for any two points $x_1, x_2\in X$ such that there exists an arc of radius $...
Fedor Nikitin's user avatar
2 votes
1 answer
1k views

Finding integer points inside of a parallelogram

Suppose $P = \{p_1,\ldots,p_4\} \in \mathbb{R}^2$ defines a quadrilateral (here, specifically, a parallelogram). In the particular case I'm dealing with, I know that there exists at least one point ...
Eric Tressler's user avatar
9 votes
5 answers
13k views

Get a point inside a polygon

I have a 2D polygon of arbitrary geometry. I need to find any point that is inside of that polygon. Taking the center won't work, because the polygon might not be convex. Is there a way to quickly ...
user10306's user avatar
  • 201
3 votes
3 answers
2k views

Is there a simple criterion to determine if two parallelograms intersect?

Assume we are given two parallelograms in the plane. How can I check if their intersection is nonempty? Note that I do not need to actually find the intersection.
Philipp's user avatar
  • 979