All Questions
1,897
questions
1
vote
2
answers
55
views
Efficient coordinate indexing
I have a triangle list, that has XYZ cooridnates per triangle node. I need a list of nodes and a list of triangle node indices from that. Close nodes should get the same index.
My C# code is:
/...
- 626
2
votes
4
answers
67
views
Find the smallest polygon with a certain edge on a 2d dijkstra graph
Sorry for bad English.
It's somehow called Minimal Cycle Basis of graph algorithm.
I'm currently working on some algorithm to seperate a graph into rooms. Like the example.
I have a graph link like ...
- 21
2
votes
2
answers
105
views
How to locate the most sparse point within a defined 2D region?
The core of the problem is to algorithmically determine the coordinates of the point E that maximizes the distance to the nearest other point in the bounded 2D space.
For example, in the space defined ...
- 440
3
votes
2
answers
88
views
Fastest algorithm for filling overlapping rectangles of pixels
I have an image. The pixel value is either 0 or 1. All pixels are initially zero.
Given a set of overlapping rectangles characterized by (bottom left pixel coordinate, width, height), I need to flip ...
- 1,654
1
vote
0
answers
34
views
Which algorithm should be used to merge free hand drawings like lasso tool - add mode?
I'm trying to make an application that merge user free hand drawings, like lasso tool add mode in photoshop.
I tried to find the algorithms but I failed it (https://www.sciencedirect.com/topics/...
- 23
2
votes
2
answers
92
views
Creating a short, d-dense list of points on the sphere S^4 in Python
I am a mathematician and this is my first time using Stack Overflow, sorry if the question is not adequate or there is some better place to ask this. I would like to know if there is a standard way ...
- 121
0
votes
1
answer
83
views
While finding count of points inside some shape using KD-Tree, do we need to check areas intersection, or just compare depth-appropriate properties?
Let's say we have to find count of points inside some shape in 2D plane.
We can use KD-Tree to solve this. The KD-Tree will partition 2D plane into rectangles, and then we can check intersections ...
- 770
1
vote
1
answer
84
views
How to find the largest isosceles trapezium with a set center inscribed in a closed polygon?
I need to find the largest (biggest area) isosceles trapezium inscribed inside a polygon, and the trapezium must have a set center.
The polygon is defined by an array of points in 2D. The polygon is ...
- 29
0
votes
0
answers
37
views
Hatching algorithm for binary bitmap
I try to develop an hatching algorithm, which can create an hatching based on a binary bitmap.
The result should look like in the example image:
Input data is a binary 2D array (bitmap)
For each line ...
0
votes
3
answers
53
views
How to extract outline of a grid-like plot when you have information about the lines?
I am trying to get the outline of a plot that looks like this:
As you can see I have information about not only the points but the lines so I basically want to have all the inner lines removed.
I ...
4
votes
3
answers
141
views
Finding the biggest shape possible inside a grid
I'm trying to make an algorithm, that finds the biggest possible shape with the given set of points. Each point can be connected to another one vertically, horizontally (by 1 unit) or diagonally. A ...
0
votes
0
answers
56
views
Determine start and end points of line from circle to rectangle
I have a square DIV that contains a circle (a 1-pixel circumference with transparent centre) and a rectangular DIV that's filled with a rectangle (a 1-pixel perimeter with transparent centre.)
I need ...
5
votes
1
answer
117
views
How to find the greatest possible euclidean distance we can achieve by moving using given set of vectors
That's a problem from Polish Olympiad in Informatics, called Pionek (PIO).
Given a set of not unique vectors, find the greatest possible euclidean distance in reference to (0,0) point you can achieve ...
- 770
1
vote
1
answer
65
views
Detect 2d collision Circle to Rectangle (with angle) and vice versa
Hi i'm trying to detect when two objects connect , either a circle or rectangle. I can't figure it out how to do it. Most examples/tutorials online are really math heavy Or doesn't use the Angle for ...
- 1,080
3
votes
2
answers
87
views
Closest edge to a rectangle in a plane of rectangles
I have a 2D plane (with discrete points) that contains arbitrary-sized rectangles and all rectangles are axis aligned. I have their coordinates (upper-left) and sizes (length and breadth).
Suppose I ...
- 198