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Questions tagged [graphs]

For the nodes and links sense of graph; use the visualization tag for the charting sense.

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Use cases for graph algorithms and graph data structures in finance and banking

I work in a bank and most data is in tabular format in relational databases. I have been reading about graph algorithms (page rank), graph libraries (spark graphx) and graph databases (neo4j). I would ...
Victor's user avatar
  • 611
1 vote
1 answer
201 views

Identify social users using graph embeddings

I have a social network and I want to identify the most social people in the graph. In a typical graph experiments this could have done using different network features. However, I recently came ...
Volka's user avatar
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4 votes
2 answers
4k views

How do you set sigma for the Gaussian similarity kernel?

Let's say we have $n$ two-dimensional vectors: $$\mathbf{x}_1,\dots,\mathbf{x}_i,\dots,\mathbf{x}_n=(x_{1_1},x_{1_2})^T,\dots,(x_{i_1},x_{i_2})^T,\dots,(x_{n_1},x_{n_2})^T$$ How do you set $\sigma$ ...
Diego Sacconi's user avatar
14 votes
4 answers
16k views

What are graph embedding?

I recently came across graph embedding such as DeepWalk and LINE. However, I still do not have a clear idea as what is meant by graph embeddings and when to use it (applications)? Any suggestions are ...
Volka's user avatar
  • 711
1 vote
2 answers
55 views

Graph to display differences (or lack of) in multilevel categorical data

I am trying to find an interesting way to interpret and display a set of data for the research I'm working on. Columns 2-4 show the net change from time 1 to time 2 in antibiotic coverage for ...
Cole H.'s user avatar
  • 11
4 votes
1 answer
1k views

Viterbi-like algorithm suggesting top-N probable state sequences implementation

Traditional Viterbi algorithm (say, for hidden Markov models) provides the most probable hidden state sequence given a sequence of observations. There probably is an algorithm for decoding top-N ...
Anton's user avatar
  • 243
5 votes
2 answers
1k views

In a directed graph, how to measure whether a node is more "upstream" or "downstream"?

Let's say that I have a directed graph, and for each node I want to have some measure of whether it is more of an "upstream" node (that lies at the beginning of many paths), or a "downstream" node (to ...
ampanmdagaba's user avatar
1 vote
1 answer
53 views

System to provide guide to students about getting admissions to universities of their choice or some specific courses [closed]

I basically want to build a system which will provide a student step by step guide or you can say a full route about what courses he/she should take currently or what examinations they need to clear ...
Samyak Jain's user avatar
0 votes
1 answer
166 views

Neo4j graph to cypher conversion

Is there a way or tools available to generate or retrieve cypher query from a Neo4j database ? Should we need to store cypher quries along with the graph data for regeneration ?
Sreejithc321's user avatar
  • 1,920
0 votes
1 answer
380 views

Clustering Multiple Networks

I'm looking for methods of Community Detection in networks. For example if I have a network of 100 people (each node is a person), how can I cluster nodes? What would be the best approach for grouping ...
Harpal's user avatar
  • 913
1 vote
2 answers
65 views

Why do we do citation analysis?

Pardon my question if it seems too general... I'm new to networks in general, but recently I came across a type of network called citations network. However, I couldn't figure out why we do citation ...
User1915's user avatar
  • 109
2 votes
0 answers
49 views

What is the best algorithm for deterministic belief propagation?

Here is a simple example: In a 3D space, if point A is the geocenter of a planet, point B is its north pole, and point C has a fixed latitude/longitude on the planet surface. Then the position of ...
tribbloid's user avatar
  • 121
3 votes
1 answer
106 views

Weighted degree in Multidimensional networks

Does there exist a definition for weighted degrees of multidimensional networks? I understand that the basic definition would be: Let $v\in V$ be a node of a network $G=(N,V,L)$. The function ...
Manuel's user avatar
  • 31
3 votes
1 answer
898 views

Organize TSNE data into grid

I have some data reduced by TSNE into a 2D representation, which shows clear spatial features. However, I'd like to format this into a grid – not just snapping data to the nearest grid square but ...
JeffThompson's user avatar
3 votes
1 answer
836 views

Predict a tree structure out of nodes with different features

The Problem Suppose we have a representation of a document's text layout as in the image below: Here, each rectangle represents a chunk of text (one word, an expression or even part of a sentence). ...
iulian's user avatar
  • 131
0 votes
1 answer
788 views

How to create full graph from vertex data frame with igraph?

Here is a DF which I take as a representation of my future vertices: Id Name 01 Alpha 02 Beta 03 Delta 04 Epsilon I want to get an igraph ...
Hendrik's user avatar
  • 8,667
0 votes
1 answer
298 views

How to approach graphed data for a binary classification system?

I'm looking for articles and other reading material on handling and modeling graph-shaped data for classification systems. As I've never working with graphed base machine learning anything from novice ...
NirIzr's user avatar
  • 200
2 votes
1 answer
701 views

Which algorithms should I use for recommendation system using a graph database?

Basically I'm developing a recommendation system using a graph database (specifically neo4j), and I want to apply recommendation algorithms. Since i'm using a graph database, I can see the ...
John Newman's user avatar
13 votes
4 answers
16k views

Large Graphs: NetworkX distributed alternative

I have built some implementations using NetworkX(graph Python module) native algorithms in which I output some attributes which I use them for classification ...
20-roso's user avatar
  • 680
1 vote
0 answers
317 views

Kernel on graphs and SVM : a weird interaction.

I have a collection of 80k graphs, half of them are labeled 1 (they represent the cities of France) and the other half is labeled 0 (representing cities in the USA). My goal is to create a classifier ...
Syzygyyy's user avatar
4 votes
2 answers
942 views

Finding groups of friends in social network data

I have some social network data in which I'd like to identify people who belong to a group of 5 friends. These are users who are friends with 4 other people who all are also friends with each other. ...
Eric Conner's user avatar
1 vote
0 answers
1k views

Multi Model data set Visualization Python

I have a data-set with two variable frequency values as given below ...
Sitz Blogz's user avatar
1 vote
1 answer
22 views

Network analysis applied on terms

I am dealing with textual data. Imagine a certain number of statements (they could be descriptions), each one referring to a certain process, where each process ends in one f three categories: A, B, C....
Andrea Ianni's user avatar
3 votes
1 answer
220 views

Is it ideally correct to benchmark neo4j as graph processing platform?

I would like to know if neo4j can be considered a graph processing platform, even though i know that: neo4j: is a graph database management system developed by Neo Technology, Inc. Described by its ...
John Newman's user avatar
4 votes
1 answer
2k views

Link prediction benchmark datasets

I'd like to test a new algorithm for link prediction on graphs. I'm interested in both weighted/unweighted and directed/undirected graphs. What are some common benchmark datasets that researchers ...
pir's user avatar
  • 790
4 votes
1 answer
4k views

Application of ideas from graph theory in machine learning [closed]

I work with neural networks (ConvNNs, DeepNNs, RNNs/LSTMs) for image segmentation and recognition and Genetic Algorithms for some optimization problems. Recently I started to learn some deep graph ...
Alex's user avatar
  • 767
8 votes
3 answers
12k views

Visualize graph network with more than 30k edges

I have a dataset with users connection and I want to create a directed network graph. Nodes: ~20.000 Edges: ~33.000 I used to work before on NodeXL and Gephi, but now I am on Mac and I don't have ...
Tasos's user avatar
  • 3,930
0 votes
1 answer
280 views

source and target functions in igraph package in R

What are the source and target functions in igraph package in R? so that source(s->t) = s and target(s->t) = t I am working on this directed graph example: ...
Hamideh's user avatar
  • 940
3 votes
0 answers
1k views

How to predict Estimated Time for Arrival given only trajectory data and time?

I have data of latitude, longitude and timestamp. I am trying to build a graph based on pincodes (in India) (equivalent to zipcode). Based on this graph and trajectory data that I have, I want to ...
user825828's user avatar
2 votes
1 answer
44 views

How to apply K-Medoids in many CFG?

I am having around 1000 DAG(Directed Acyclic Graph) of different files showing java.io.BufferedReader usage. Following is representation of one of the graphs ...
Prateek's user avatar
  • 121
2 votes
0 answers
177 views

Visualizing a big number of polynomials as atlas of graphs?

Suppose you have a big number of polynomials such as xyz+xy+z where xyz, xy and ...
hhh's user avatar
  • 171
4 votes
1 answer
130 views

What is a Recurrent Heavy Subgraph?

I recently came across this term recurrent heavy subgraph in a talk. I don't seem to understand what it means and Google doesn't seem to show any good results. Can ...
Ghazanfar's user avatar
  • 143
2 votes
1 answer
1k views

How to make edges appear in a graph when adjacency matrix value is beyond a particular threshold?

I've created a graph from an adjacency matrix using the igraph package but I want edges to appear in the graph only when the value in the adjacency matrix is beyond a particular threshold. Using the ...
amankedia's user avatar
-1 votes
1 answer
4k views

How to convert a 2D matrix into a graph object in R

set.seed(42) iris_matrix <- as.matrix(iris[,1:4]) image(iris_matrix) g<-cor(iris_matrix) g library(igraph) independent.vertex.sets(g, min=NULL, max=NULL) ...
amankedia's user avatar
1 vote
1 answer
101 views

Algorithm to construct similarity structure from hash lookup table

I have constructed a lookup table using locality-sensitive hashing for comparing nearly similar documents/records. If two records (columns) have the same hash value in a row, they are considered to be ...
DonDyck's user avatar
  • 113
9 votes
1 answer
12k views

What is the difference between affinity matrix eigenvectors and graph Laplacian eigenvectors in the context of spectral clustering?

In spectral clustering, it's standard practice to solve the eigenvector problem $$L v = \lambda v$$ where $L$ is the graph Laplacian, $v$ is the eigenvector related to eigenvalue $\lambda$. My ...
felipeduque's user avatar
3 votes
1 answer
92 views

Hub removal from graphs

I have a graph with vertices that represent some entities and the edges are weighted as the correlation between two such entities. I would like to break this graph into several subgraphs with high ...
scf's user avatar
  • 185
0 votes
2 answers
2k views

collaborative filtering using graph and machine learning

What are the advantages and disadvantages of using Collaborative filtering based recommendation using machine learning approach and graph based approach ? Say I have user purchase data (user_name, ...
Sreejithc321's user avatar
  • 1,920
1 vote
0 answers
31 views

Designing an (RL) agent for a graph-based music improvisation system

I am trying to implement a simple agent that creates sounds by building up signal building blocks (e.g. sound generators, filters etc.) that can generally be connected in the form of a directed ...
0__'s user avatar
  • 111
2 votes
1 answer
76 views

Estimating destination according to previous data

I need an advice. I can resume my problem like that : I have some travels in a database, for example : ...
Sony's user avatar
  • 123
1 vote
1 answer
539 views

Website navigation path using graph theory

In web analytics, one of the main issues is to find the optimal path of navigation. Question: Is there any literature in graph theory area, which is focused on studying optimal website navigation path?...
Beta's user avatar
  • 237
5 votes
1 answer
894 views

Cluster directed graph into DAG

I am looking for an algorithm that clusters a directed graph into a set of clusters that form a directed acyclic graph. For example, given: nodes: {A, B, C, D} with edges: {(A,B), (B,A), (A,C), (C,D),...
Ben's user avatar
  • 51
2 votes
1 answer
65 views

What makes a graph algorithm a good candidate for concurrency?

GraphX is the Apache Spark library for handling graph data. I was able to find a list of 'graph-parallel' algorithms on these slides (see slide 23). However, I am curious what characteristics of these ...
sheldonkreger's user avatar
3 votes
1 answer
3k views

Is there any working alternatives to Netvizz? [closed]

I'd like to download my friends data as a graph/network from Facebook. In Feb 2015, Facebook banned the awesome application Netvizz. Do you know any alternative application for my purpose?
Übel Yildmar's user avatar
4 votes
1 answer
148 views

Traversing trees in SQL: JOINs vs imperative algorithm

I have a table representing posts on a message board. Posts may or may not have parents. What is the most common way to get all posts starting from a given post, or to find the root post of any given ...
blue-dino's user avatar
  • 383
5 votes
1 answer
3k views

Learning time of arrival (ETA) from historical location data of vehicle

I have location data of taxis moving around the city sourced from: Microsoft Research Overall it has around 17million data points. I have converted the data to JSON and filled up mongo. A sample ...
Spiralarchitect's user avatar
4 votes
1 answer
183 views

Why are HMMs called linear-chain?

I found in many sources that Hidden Markov Models are linear-chain networks(e.g. in Predicting Structured Data book by MIT). However, as I understand it, HMMs can have any edges in its graph. Even ...
generall's user avatar
  • 273
0 votes
1 answer
270 views

Canonical VS Graph Isomorphism [closed]

I'm having a having a hard time understanding the difference between an isomorphism in graphs and canonical graphs. I have read through the Wikipedia articles, but it still isn't clicking. Can ...
sheldonkreger's user avatar
2 votes
1 answer
127 views

Computation of a column-stochastic matrix with target row sums

I want to generate an $N\times N$ matrix $A$ so as to target an $N$ vector of row sums and simultaneously all column sums should sum to 1. In addition to this, I have a prefixed number of elements ...
Piyush Panigrahi's user avatar
1 vote
1 answer
166 views

Graph layout for a network of molecules

I am looking for a suitable graph representation where the nodes/vertices are molecules with 2 main variables: structural characteristic and a real number property (for example biological potency). ...
user8218's user avatar