connected-components

Find connected components in list of triangle vertices

风格不统一 提交于 2020-05-16 05:53:10
问题 Consider two graphs, G1 = (V1, E1), G2 = (V2, E2) V1 = {1,2,3,4,5,6} V2 = {7,8,9,10,11,12} In space, these vertices are connected by triangles faces (each with three vertices) F1 = [[ 2, 1, 0], [ 0, 3, 2], [ 1, 4, 0], [ 0, 4, 3], [ 5, 1, 2], [ 3, 5, 2], [ 5, 4, 1], [ 4, 5, 3]] F2 = [[ 8, 7, 6], [ 6, 9, 8], [ 7, 10, 6], [ 6, 10, 9], [11, 7, 8], [ 9, 11, 8], [11, 10, 7], [10, 11, 9]] The above is what I am trying to find. If we are given the entire array of faces: faces = [[ 2, 1, 0], [ 0, 3, 2

Python iterate through connected components in grayscale image

你离开我真会死。 提交于 2020-02-19 05:07:48
问题 I have a gray scale image with values between 0 (black) and white (255). I have a target matrix of the same size as the gray scale image. I need to start at a random pixel in the gray scale image and traverse through the image one pixel at a time (in a depth-first search manner), copying its value to the corresponding location in the target matrix. I obviously need to do this only for the non-white pixels. How can I do this? I thought that I could get the connected components of the gray

Python iterate through connected components in grayscale image

橙三吉。 提交于 2020-02-19 05:05:31
问题 I have a gray scale image with values between 0 (black) and white (255). I have a target matrix of the same size as the gray scale image. I need to start at a random pixel in the gray scale image and traverse through the image one pixel at a time (in a depth-first search manner), copying its value to the corresponding location in the target matrix. I obviously need to do this only for the non-white pixels. How can I do this? I thought that I could get the connected components of the gray

Getting connected components of graph in Prolog

早过忘川 提交于 2020-02-03 18:59:29
问题 I'm struggling with logic programming. I have a this problem and I hope some of you can help me with it. Discontinous graph is represented by facts in this way: h(0,1). h(1,2). h(3,4). h(3,5). So there is two separate graph components. I would like all the separate components on the output represented by a list. So if there is three separate components in the graph, there will be three lists. For the given example above, the expected output is [[0,1,2],[3,4,5]] . 回答1: Using iwhen/2 we can

use cv2.connectedComponentswithstats to display images

Deadly 提交于 2020-01-25 06:51:11
问题 I have an image and I want to remove the white small dots from the image. I read many post and found cv2.connectedComponentsWithStats would work. But how to display the images using its output.Below is my code : import cv2 import numpy as np from matplotlib import pyplot as plt src = cv2.imread("./folder/0607130001-1.png",0) binary_map = (src > 0).astype(np.uint8) connectivity = 4 # or whatever you prefer output = cv2.connectedComponentsWithStats(binary_map, connectivity,cv2.CV_32S) plt

How to aggregate matching pairs into “connected components” in Python

十年热恋 提交于 2020-01-20 16:51:27
问题 Real-world problem: I have data on directors across many firms, but sometimes "John Smith, director of XYZ" and "John Smith, director of ABC" are the same person, sometimes they're not. Also "John J. Smith, director of XYZ" and "John Smith, director of ABC" might be the same person, or might not be. Often examination of additional information (e.g., comparison of biographical data on "John Smith, director of XYZ" and "John Smith, director of ABC") makes it possible to resolve whether two

How to aggregate matching pairs into “connected components” in Python

不想你离开。 提交于 2020-01-20 16:45:34
问题 Real-world problem: I have data on directors across many firms, but sometimes "John Smith, director of XYZ" and "John Smith, director of ABC" are the same person, sometimes they're not. Also "John J. Smith, director of XYZ" and "John Smith, director of ABC" might be the same person, or might not be. Often examination of additional information (e.g., comparison of biographical data on "John Smith, director of XYZ" and "John Smith, director of ABC") makes it possible to resolve whether two

Create an adjacency list type structure from a list of pairs

白昼怎懂夜的黑 提交于 2020-01-14 14:42:29
问题 In C#, I have class Pair{ int val1; int val2; } I have a list of pairs coming from a source as:- List<Pair> sList = new List<Pair>(); 1 | 2 2 | 3 1 | 4 4 | 6 I need to convert it into the following type of structure:- [1, [2, 3, 4, 6]] [2, [3]] [3, [2]] [4, [1,6]] [6, [4]] What is the best way to go about this (without LINQ)? 回答1: I would go with an ILookup<int, int> , but you need to include the reverse associations as well: var result = sList.Union(sList.Select(p => new Pair { val1 = p.val2

How to get connected components in graph analysis without using graphframes pyspark library?

谁都会走 提交于 2020-01-03 05:17:31
问题 This is in continuation of my earlier post and being advised to open another question. My problem statement is to get connected component id in pyspark(preferred) without using graphframes as my enterprise spark setup does not have this library. I was advised to use the code at the link: https://mlwhiz.com/blog/2018/12/07/connected_components/#connected-components-in-pyspark I have a list of edges as tuples of the graph. I am using the below code to create the adjacency list: from itertools

Need to find sub graphs from one big graph using boost::graph

浪尽此生 提交于 2020-01-03 05:13:11
问题 PH -> PH1 PH -> PH2 PH1 -> N1 PH1 -> N2 PH2 -> N3 PH2 -> N4 required output as : sub graph 1 : PH1 -> N1 PH1 -> N2 sub graph 2 : PH2 -> N3 PH2 -> N3 回答1: This is almost trivial using connected_components . The complicating thing is to ignore the PH node. You didn't say whether this node is given or should be detected. I have written some code to try to detect it. Let's Start #include <boost/graph/adjacency_list.hpp> using Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost: