# Questions tagged [computational-geometry]

Computer geometry is a branch of computer science devoted to the study of algorithms which can be stated in terms of geometry.

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### Calculating the term of dfdeta [closed]

I am trying to improve the time running of this code. Some dummies variable is defined and it is just some part of a lot of lines of code, but I tried it with dummies variables. It takes too much in ...
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### Find overlapping area of octagons

Here is my problem statement: There is a matrix of octagons, for example, 4 octagons in a row and 3 such rows. So 4 columns and 3 rows of octagons. But they are not arranged in a perfect rectangle ...
57 views

### Compute angular distances between data points in a matrix

I am having a hard time speeding up a function that I use to compute angular distances between data points in a matrix. More precisely, I want to compute \sum_{r=1}^n|\pi - \arccos\left(\frac{(X_{i}-...
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### A program for fun to see how red and blue appears blended to purple due to resolution

I do some art both analog and digital. This time I did some color test digitally. To work on my programming skill so that it's shareable I'm asking for help to get some code review. How's the ...
1k views

### Generate points for smooth movement between two given points

This is one of the methods in a project for generating points between two given points. We add points of route with a 25ms delay in an array and a camera on Google Maps is always at the last point. So ...
607 views

### Counting the triangles that can be formed from segments of given lengths

Problem Statement: Given an unsorted array of positive integers. Find the number of triangles that can be formed with three different array elements as lengths of three sides of triangles. ...
32 views

### Find intersection of rectangle with itself rotated

Given $w, h, \alpha$ for a rectangle centered at origin with width $w$, height $h$ and itself rotated by $\alpha$ around origin clockwise, I wrote a code to find the intersection area. ...
77 views

### Read coordinates from many files and calculate polygon areas

My goal with this snippet is to create an array of coordinates which in turn is a tuple of 68 elements, area and modified area array for all 10k elements and assign it to the ...
1k views

### Determine if a triangle is equilateral, isosceles, or scalene

I've been fiddling around with some easy code challenges and there's one about determining if a triangle is equilateral, isosceles, or scalene. I've come up with a working solution, but I feel this ...
82 views

### Find 4 points which form a square with the biggest area

I have set of points on the coordinate plane. I need to find the 4 points which form a square with the biggest area. I'm new in JavaScript so I'd like to get any suggestions about code style, ...
112 views

### Choosing evenly distributed points from a million points on a sphere

I have $10^5$ to $10^6$ points on a sphere, and want to choose some points from them which are as close as uniformly distributed as possible. For that reason, I do the following: at each step I ...
990 views

### Cubic spline interpolation in Python from scratch

I implemented the cubic spline interpolation explained in https://en.wikipedia.org/wiki/Spline_interpolation as a Python class. Of course, such an interpolation should exist already in some Python ...
208 views

### Find all k points which are closest to origin

We have a list of points on the plane. Find the K closest points to the origin (0, 0). (Here, the distance between two points on a plane is the Euclidean distance.) You may return the ...
218 views

### Searching extreme points of polyhedron

In my Uni, my scientific professor asked me to make some researches about the extreme points of polyhedrals. And I did them. I found that there is still no code in public for searching extreme points ...
171 views

### Line segment intersection from [de Berg et al, 2000], computational geometry

I've implemented the following algorithm (From "Computational Geometry : Algorithms and Applications"). The code is below: (All the code actually is here: https://github.com/lukkio88/...
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### Given a list of coordinates, find the rectangle with minimal area

A problem on leetcode asks the coder to write an algorithm to take a bunch of coordinates in the xy-plane and return the minimum area of a rectangle made from four of these coordinates (or return <...
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### Project Euler Problem #102 in F#: counting triangles that contain the origin

I've recently decided to get into functional programming with F#, and decided to learn the language through Project Euler. The following is my implementation of problem 102: Problem: Three ...
62 views

### Optimal algorithm to move a a rope from one position to another

I'm an engineer working with a deformable membrane that is attached to actuators. The goal is to move the membrane from one shape to another, without ripping the membrane. This imposes "neighbor ...
120 views

### Computing bezier curves of degree n with recursive functions

I have been looking at homemade CNC and have been wondering how curves are drawn, so I looked into it and found this cool article. I then decided to try coming up with a bezier curve algorithm in C. ...
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### Implementing Cyrus Beck algorithm for convex polygons

I have found the coordinates of the centroid for finding the direction of the normal vectors of the edges of the convex polygons. This method seems to work in the cases I tested. Is this fool proof ? ...
61 views

### Get directions for unit movement with conditions

I am developing a bot for Starcraft II. In my code for unit movement, I often find myself doing this: Calculate points around the current position of the unit Check if these points are valid and can ...
203 views

### AI to avoid obstacle

The AI I'm making is really simple, however it might be a bit too inefficient for what it is doing. The chart below shows speed differences between various arithmetic and math operations. ...
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### Graham Scan Algorithm in Haskell

I have just begun learning functional programming and Haskell. This is my attempt to implement a solution to Graham Scan Algorithm in Haskell. Note that I am not even sure if this is indeed Graham ...
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### Determine whether path A→B→C on a plane constitutes a left or right turn

I have recently started learning functional programming and Haskell. I have encountered this problem: Consider three two-dimensional points a, b, and c. If we look at the angle formed by the line ...
163 views

### Where is the most desolate place in Colorado?

The Story While flying a plane over the forests of Wisconsin a couple years ago, I thought to myself "If I lost an engine, I would be awfully long way from an emergency landing airport. I wonder ...
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### Drawing concentric circles to console

This prints out a triple layer circle with 12 points per circle and finds the points across a grid. I had a really hard time with this and I'm planning to implement a lot more code but I don't want ...
4k views

### Intersection over Union for rotated rectangles

Problem Statement I am trying to find the intersection over union (IoU) metric for one to several rotated rectangles compared to many different rotated rectangles. Here are some images to help ...
1k views

### Function to calculate distances and nearest points between 2 GeoPandas dataframes

I have 2 geoPandas frames and want to calculate the distance and the nearest point (see functions below) from the geoSeries geometry from dataframe 1 (containing ...
1k views

### Program to see how many points lie strictly inside a convex polygon

The program takes in a set of coordinates that defines the polygon. It then takes in a set of points. The idea is to find out how many of these points lie strictly inside the convex polygon (not on ...
82 views

### Curvature data to coordinates

I want to determine a path (x and y coordinates) by using curvature data (radius, with constant distance (length_of_arc) travelled between data points. I want to ...
894 views

### Given a list of coordinates check if 4 points make a line

I was doing some preparation for coding interviews and I came across the following question: Given a list of coordinates "x y" return True if there exists a line ...
62 views

### Checking where/if another creature lies in a creature's field of view

Note: this is a more specific form of this I am working on a simulation of some virtual creatures. They all have vision that lets them see other creatures. To do this, I calculate the difference ...
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### Finding the closest pair of points divide-and-conquer speed improvement

This is a follow up to a previously asked Finding the closest pair of points divide-and-conquer question . The original code changed significantly based on answers from @AJNeufeld therefore I created ...
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### Finding the closest pair of points divide-and-conquer

Here is my code for the famous "finding the closest pair of points" problem from CLRS book section 33.4 using a divide-and-conquer approach (this code returns the minimum distance between pair of ...
474 views

### Finding the distance between the two closest points in a 2-D plane

Here is my code: ...
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### Lagrange Interpolation over quadrilateral points

I've been working on a program which calculates, given a point and 4 surrounding points, the Lagrange polynomial, in order to interpolate a value. Consider that I'm not a mathematician and I better ...
168 views

### Math matrix, mainly for graphics

I wrote a matrix library to replace my old matrix library. I was using my old matrix library to do basic operations for 3D rendering but that library grew old and now I'm seeking to replace it. I'm ...
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### Draw common tangents to two circles interactively in MATLAB

Requirement After a user draws two circles with their mouse successively, the program should draw all common tangents, if any, to them. Here is my implementation ...
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### Solving for <45 degree angles of a multi-vector system

I'm working on a problem from codechef.com. The goals are: Solve for whether or not the driver took a "sharp turn", meaning for some angle θ, θ > 45°. Test each point $(x_i, y_i)$ in the system ...
868 views

### Given points on a 2D plane, find line that passes through the most points

Could someone give some feedbacks from perspective of oo design and coding style on the following codes: Question: Given n points on a 2D plane, find the Line with maximum number of points that lie ...
215 views

### Angle reflection function

I've developed a function to calculate the exit angle of a projectile after it collides with a boundary/edge inside a rectangular space, based on the entry angle and the axis it is colliding with. ...
120 views

### Finding angle and direction between line segments

I'm putting together a short demo on two things: Finding the angle between two line segments and direction (right or left) as you travel counterclockwise around a shape Using newer ecmascript syntax (...
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### Calculating minimum size of rectangle that contains two smaller ones [closed]

My Rectangle class contains one vertex (x,y), its width a, and its height b; the opposite ...
75 views

### Catmull-Rom Interpolator: Template pandemonium avoidance

I have a pull request implementing Catmull-Rom interpolation. I have gotten it pretty fast-to ~25 ns/call-but I feel the design is not enlightened. The code is here, and reproduced below: ...
80 views

### Segment road map data with heuristics

Backstory A little while ago I was assigned with the task of clustering some road segments using open street map data. After parsing a huge XML (maybe that should be another review) I ended up with ...
3k views

### Area of the triangle generated by the hands of a clock

Problem explanation: Let’s suppose we have a clock that has an hour hand 3 units long, a minute hand 4 units long, and a second hand 5 units long. The hour hand moves once every hour, the minute hand ...
1k views

### Triangle area computation and linear transformations

I have a task to learn how to write clear and understandable documentation of written code in python. Please, can you give me a feedback to attached code below? I need to know if the code and comments ...
79 views

### Yaw (Z-rotation) angle linear interpolation without quaternions

I need to write a function performing linear interpolating between two Euler angles in 2D, perfectly without the use of quaternions as conversion seems to be an overkill for such a simple task. Here'...