Questions about handling graphs in Mathematica, graph theory, graph visualization, GraphPlot, the built-in Graph type and the Combinatorica` package.

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3
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0answers
221 views
3
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2answers
198 views

How can I construct “better” block graphs?

A graph is a block graph if it can be constructed from an undirected tree by replacing each edge with a clique. My method of generating "random" block graphs is as follows. The parameters are the ...
7
votes
1answer
176 views

How to scale edge length and keep layout of edge-weighted Graph?

I love using Graph as structure to store and visualize my data in Mathematica. Consider the following simple example for creating a ...
0
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0answers
122 views

Pearl's Message Passing Algorithm

Has anyone tried to implement the Message Passing algorithm using Mathematica's Graph/Combinatorica features?
1
vote
1answer
150 views

Find size of vertex image relative to the graph coordinate system

I am trying to define a graph using my own VertexShapeFunction with an ActionMenu button being the vertex and a custom ...
5
votes
2answers
307 views

How to add new nodes to an existing graph with fixed (coordinates) nodes?

I'm ultimately trying to create a directed graph with some of the nodes in fixed positions and the other nodes placed around them in "acceptable" positions. It's better if I ask the question by ...
1
vote
1answer
94 views

FindEdgeCut with weighted graphs

If I want to find a minimum cut between two nodes in a weighted graph, I would use FindEdgeCut as follows: ...
0
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1answer
105 views

How can I replace UndirectedEdges to pairs of bi-directional DirectedEdge in a Graph?

How can I have pair of edges between nodes in this kind of graphs? ...
3
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1answer
172 views

Vertex Labeling Problem in a Graph

I am using following codes to create a graph. ...
10
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1answer
509 views

Roads network visualization by thickness and color intensity by population from GIS files

We can have road networks of the countries in GIS shape file.For exmple from here. Normally traffic flows are proportionate to populations of the cities. I wonder how we can have the same in ...
5
votes
1answer
71 views

Setting PropertyValue for VertexWeight is not persistent

g = CompleteGraph[8, VertexSize -> Medium]; PropertyValue[{g, VertexList[g][[1]]}, VertexWeight] = 10; PropertyValue[g, VertexWeight] ...
1
vote
1answer
90 views

Is there a TwoColoring function of Graph object?

The following code shows the GraphUtilities package makes a problem for Graph object. I want to use a ...
5
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1answer
471 views

All possible topological orderings of a graph

TopologicalSort[] returns one of many unique orderings. From wikipedia: if a topological sort does not form a Hamiltonian path, the DAG will have two or ...
9
votes
1answer
105 views

FindHamiltonianCycle is not invariant to edge permutation

Found this bug-like behaviour today: if the order of edges is changed so that VertexList does not return the vertices in canonical order, ...
3
votes
1answer
49 views

Problems with PropertyValue when Graph's vertices are Lists

I create a Graph which vertices are lists (points in n-dimensional space) ...
3
votes
1answer
150 views

How can I highlight and individually color the connected components of a graph?

I have a graph G, and I wish to individually highlight and color the different connected components of a graph. It is simple enough to do this for one component: ...
1
vote
1answer
158 views

Do any users know of methods to capture Twitter feeds and subject them to analysis? [duplicate]

I would like to use the output of about 300 Twitter sources and would probably collect 30 minutes of tweets at a time and subject each collection to analysis; ideally this process would be automatic ...
1
vote
2answers
113 views

Separating disconnected graph objects without losing vertex coordinate assignments

Say I have a graph Gtest, which has multiple disconnected components. I found that I can isolate individual components while retaining vertex coordinate ...
0
votes
1answer
35 views

Parsing output from FindHamiltonianCycle to recover an ordered list of vertex positions for a discovered path

After applying FindHamiltonianCycle to a graph, one generates output that looks like the following: ...
1
vote
2answers
492 views

How do I divide the columns of a matrix by the sum of its elements?

I am trying to create a transition matrix for a network. In order to do this, I need to sum down the column (the out degree), and then divide the column by the out degree in order to normalize it. ...
5
votes
1answer
143 views

Keeping vertexcoordinates after adding a new vertex

I want to add a new vertex to a graph, with fixed VertexCoordinates but when I use VertexAdd, the new graph does not have the VertexCoordinates of the previous one. ...
12
votes
4answers
1k views

Finding elementary cycles of (directed) graphs

I need to enumerate all the simple cycles (i.e. elementary cycles where no vertex is repeated other than the starting) of a graph which has both directed and undirected edges, where we can treat the ...
1
vote
2answers
318 views

EdgeRenderingFunction question

(Edit 1 : I added this paragraph after the original post, for context) Some context for this question can be found in another post (Problem with EdgeRenderingFunction), which however may be taken ...
6
votes
2answers
336 views

Sierpinski carpet with GraphData

Is this graph in the list among the so-called "standard" structures used in GraphData? However, I have not found, yet, anything like "Carpet" or "Sponge" in the ...
14
votes
3answers
996 views

Creating diagrams for category theory

Lately I've been doing algebra and I have found myself drawing a bunch of diagrams when I attempt to solve a problem. Most of the diagrams are very simple so I thought, I bet I can do this in ...
3
votes
4answers
450 views

Graph Creation in Mathematica: TSP

I'm trying to create the following graph in Mathematica Where do I start? I'm specifically trying to make a graph so that I can use it in TravelingSalesman[g], ...
2
votes
3answers
175 views

Graph with $\{a,b\}$ as Vertex Instead of Number

I'm trying to create a graph which has $\{a,b\}$ as labels: ...
9
votes
1answer
347 views

Drawing Zonotopes from Adjacency Matrix

This is crossposted in cs.stackexchange.com, but I have been trying to use Mathematica do this and figured it might be more appropriate to ask here. Define a "simple zonotope" to be a regular ...
3
votes
2answers
216 views

TreePlot EdgeLabeling Style

I am trying to control the style for edge labels in treeplot and have run into a problem. Consider these two graphs: ...
10
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1answer
433 views

Drawing dessins d'enfants (bipartite graphs subject to certain conditions)

I want to write a function which constructs all possible dessins d'enfants (bipartite graphs fulfilling certain criteria, given below) from a collection of data presented in the following form: ...
1
vote
0answers
116 views

Network problem of visualization of vertex

I have a question about visualization of network in Mathematica: for example: for this network g = ExampleData[{"NetworkGraph", "Friendship"}]; when we ...
5
votes
2answers
319 views

Colorize and the Four-Color Theorem

We can write: MorphologicalComponents[image] // Colorize To assign a random set of colors to each component in some image. The example used for reference by ...
6
votes
5answers
457 views

Building graph based on the cities connection?

I built a Graph based on the permutations of city's connections from : ...
7
votes
3answers
366 views

I can't understand FindShortest Tour

I can't understand the function FindShortestTour because of the result: FindShortestTour[{ {0, 1}, {5, 1}, {2, 1}, {10, 1}}] ...
2
votes
1answer
162 views

How to set FindGraphCommunities Modularity's method option

It is possible to set 2 options for one of FindGraphCommunities's methods "Modularity". They are "Weighted" and "StopTest". The question is how can one use the second option "StopTest"? What ...
6
votes
1answer
155 views

Graph rendering not working as expected

I'm running the older Mathematica v6 which seems to go through the edges of graphs twice. Is this a bug? Is it fixed on the latest version? Please just try this command: ...
1
vote
1answer
485 views

Adding an image background to a graph that uses vertexposition

Hello Mathematica stackexchange community! I need your help on a research project. I'm looking to create a graph g with vertices in specifies places and then use an image I have as the background of ...
5
votes
2answers
1k views

How to find the Shortest Path, visiting ALL vertices, without coming back to the start (Hamiltonian Path, minimum distance)

A car has to pick up each person and take them to their destination. I am trying to find the shortest tour that will do this. How can I find the shortest path between any s and t.... visiting all ...
2
votes
2answers
177 views

Adding Dynamic functionality to a Graph

I would like to make the edges and vertices of a Graph interactive, a simple demonstration is to change their colors: ...
4
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2answers
243 views

Efficiently determining the largest minimum cost to travel from a fixed source to an arbitrary sink in a weighted graph

Let $v_i$ be a vertex in a graph $G$ with vertices $(v_1,...,v_N) \in V$ and edges $(e_1,...,e_M) \in E$ with associated weights $(w_1,...,w_M)$. Let $v_s \in V$ be specified vertex in the graph. In ...
1
vote
0answers
168 views

Get path to end nodes in directed (partially cyclic) graph

I have a large directed graph containing small loops. I would like to extract all paths to all end nodes (no VertexOutComponent) with a given path length $n$. I ...
9
votes
3answers
372 views

FindShortestTour for charity (or: How can I optimize meal delivery with FindShortestTour?)

I've been wondering about this for a while - but never got around to asking - until I saw faleichik's incredible answer to Mathematica Minecraft. I did some work at a not-for-profit a little while ...
4
votes
0answers
110 views

Efficient Generation of Subgraphs (or, unfriend a friend a day)

NB: If you're not interested in the back-story, you could simply jump forward to the code which I'm seeking to optimize. Also, I believe this code would only work for MMA 8.0 and above. My friends ...
1
vote
1answer
427 views

Plotting a network or a graph with given coordinates for vertices

I'm new to Mathematica yet have coded a lot in MATLAB. Currently I'm working on a network simulation. My model is implemented in MATLAB, but I need to port it to Mathematica. Here is my question: ...
6
votes
1answer
124 views

Tooltip not working in web deployed cdf

I deployed a CDF file in a web page. I used both Mouseover and Tooltip functions. They both work in the raw CDF file. The ...
2
votes
1answer
100 views

PermuteSubgraph not working? (Combinatorica)

I am trying to write a code to perform the QAP partialling analysis (here's a paper to know more) but the part in which I "scramble" the graph with PermuteSubgraph does nothing, I am actually not ...
0
votes
2answers
117 views
1
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1answer
97 views

How do I change the Head of Graph into List?

I am trying to change the Head of b (a NeighborhoodGraph) from Graph into List but Apply seems to fail. I start with a list of connected vertices: ...
8
votes
1answer
207 views

How can I sequentially apply different graph embeddings?

Imagine I have some graph G, and I perform a graph embedding using a command like: ...