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

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3answers
643 views

Graph generation given number of edges and nodes

I was wondering if it is possible to have Mathematica generate all graphs with a given number of edges and nodes (and possibly restricting the adjacencies) and draw them I know that there are some ...
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3answers
346 views

Rendering polygon as graph with directed edges in Mathematica

In Mathematica I'm trying to render a polygon as a set of vertices and directed edges. What I have so far: ...
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2answers
161 views

Graph expansion on Mathematica

Is there a way by which Mathematica can be given a graph as an input and be asked to find its expansion? Note: By "expansion" I mean the quantity called "isoperimetric number" or "Cheeger constant", ...
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2answers
149 views

Improving performance in the generation of random (directed acyclic) graphs

I need to generate large (directed, acyclic, transitive) graphs. My code in Mathematica gets very slow for large numbers of vertices. I've tried a number of approaches and I can't find any significant ...
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3answers
100 views

GraphIntersection Problem

I Have a problem when plotting 2 functions. I want to find out where the two graphs intersect eachother. That said, I want the coordinates (x, y) of the point. ...
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1answer
141 views

How to impose control over vertex-to-vertex Graph edges?

I’m working on a Markov Chain and hope there is a way to impose control over how Mathematica places edges to connect vertices in a Graph. My Markov Chain currently consists of 4 vertices with 2 of the ...
5
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1answer
522 views

How to display each step of an A star algorithm?

I wrote a pathfinding program: A*, which is an extension of Dijkstra. I want to see the result of each step at a time. Which function should I use? The main program is the notebook Astar, which is ...
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3answers
335 views

Centrality measures for single nodes

I am producing a graph, generated by a list of adjacent nodes. (The list looks like {1 ->583, 1->2977, 2->14, 4->1293, 5->221, ...}. Each node of my ...
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1answer
174 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. ...
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3answers
271 views
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2answers
242 views

Is there something wrong with VertexConnectivity

Note: this is fixed in version 10. As I noticed in the documentation VertexConnectivity is defined as the following The vertex connectivity of a graph $g$ is ...
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2answers
401 views

Merging (combining) tables of graph relationships (2-mode to 1-mode network)

I have some data of corporate board members in Australia in excel format here (Dropbox public link). It is the data behind this graph. The first worksheet is of all the vertexes (directors and ...
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2answers
220 views

How can I preserve the properties of edges of the original graph $g$ in a subgraph that doesn't include every edge of $g$?

The closest question to the following I could find was Preserving labels when using graph functions, but it doesn't seem to cover this. Consider a graph g where ...
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2answers
276 views

Is there something akin to “SubgraphIsomorphismQ” in Mathematica 9?

Provided two unlabeled graphs, $G$ and $H$, I would like to test where $H$ is a subgraph of $G$. In other words, I'd like to test whether we can prune some fixed number of vertices or edges from $G$ ...
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2answers
143 views

Test existence of a path from one side of a graph to another

I'm trying to determine how I can test if a path exists from one side of a graph to another as efficiently as possible. If I have the Lines given by: ...
5
votes
3answers
692 views

Fast code to generate large random graph with fixed degree sequence

I'm trying to create a function so to generate large random graph with a fixed degree sequence $\{v_1,v_2,\dots,v_N\}$, where $N$ is the number of vertices in the graph. The Mathematica function that ...
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1answer
733 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 ...
5
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2answers
480 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 ...
5
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2answers
238 views

Graph does not evaluate some options when not displayed

How can I force Graph to evaluate all its options without actually displaying the graph itself? Evaluating the following code ignores the ...
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1answer
416 views

Accessing the graph Thinning produces without losing all the edges' lengths/slopes

This is a follow up to the OCR question I had earlier. What I want to do is to use Thinning to create "skeletons" of images of characters and then compare their shapes, utilizing such properties ...
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1answer
1k views

When do I use Mathematica, when do I use Gephi, and how do I use them together?

Mathematica has great operations for analyzing graphs but when the graphs are a bit bigger, Gephi seems to be more efficient (at least on my computer) at drawing and analyzing, i.e. visualizing the ...
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1answer
86 views

How to use DegreeGraphDistribution with directed graphs?

DegreeGraphDistribution supports directed graphs because it has a DirectedEdges option. How can I specify the in-degree ...
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1answer
88 views
5
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1answer
255 views

Processing and storing a graph with a large number of vertices s.t. k-hop neighborhoods are efficiently retrievable

I have an unweighted, undirected graph $G$ with $(v_1, ..., v_N) \in V$ vertices, where each vertex in the lattice represents a string of some length ($\leq 200$ characters), and I need to construct ...
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1answer
278 views

How can I compute the chromatic index and number of a graph?

I saw a recent question from M.R. and realized there is no function to compute the chromatic index and number of a graph, other than a really slow method in the now deprecated Combinatorica. So, how ...
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1answer
255 views

Implementing local complements of graphs

I'm trying to write a routine which generates the local complement of a graph at a vertex. For those who don't know, the local complement for a singly-connected, undirected graph is defined as the ...
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1answer
160 views

Why do vertex labels disappear when I edit with drawing tools?

I'm trying to change the text and arrow style in GraphPlot using the drawing tool, but the the vertex labels disappear when I do that: ...
5
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1answer
262 views

How do I find a weighted bipartite graph's minimum edge cover using Mathematica 8?

In graph theory, we use the Hungarian Algorithm to compute a weighted bipartite graph's minimum edge cover (a set of edges that is incident to every vertices, the one with the minimum total weight.) ...
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1answer
80 views

Finding the minimum vertex cut of a graph

It seems that Mathematica is not correctly finding the smallest set of vertices that will disconnect a graph. Here is an example: ...
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0answers
71 views

Graph: PropertyValue changes and Dynamic

I almost never work with Graph in Mathematica but lately I helped someone with it. For this, I tried to make an animation using ...
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0answers
161 views

How to draw block diagrams as Graph objects?

In the documentation ClosedLoopResponsesWithAPIDController, There is a very nice block diagram. I want to create my own block diagrams similar to this. I clicked on the diagram and pressed ...
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0answers
163 views

Citation of the algorithms used in FindGraphCommunities

For my research work I need to put a comparison of different community detection algorithms. Instead of implementing all those algorithms once again, I would like to use the methods already provided ...
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0answers
71 views

Graph relationships between functions and variables [duplicate]

Possible Duplicate: Has anyone written any function to automatically build a dependency graph of an arbitrary Mathematica function? I need to make sense out of a huge notebook (17Kloc) ...
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2answers
248 views

Coordinate extraction and manipulating graphs as graphics objects

Consider the image below: GraphData[{"Wheel", 7}] Is it possible in Mathematica to lay several of these Graph along each ...
4
votes
3answers
800 views

How to find all graph isomorphisms in FindGraphIsomorphism

I found the second definition of the function FindGraphIsomorphism not working. Here's the definition Mathematica 8 gives: ...
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2answers
190 views

Visualize difference between members of the list

I want to visualize the difference between members of a set: set = {20, 36, 70, 96, 152, 301} This way I get the diffs: ...
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4answers
600 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], ...
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3answers
207 views

Graph Coloring based on neighboring vertices? Cellular Automata

I would like to apply a majority rule cellular automata to graphs. Specifically, I would like to take a graph as input, and then define two functions, InitialColoring[graph] and MajorityRule[graph]. ...
4
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2answers
82 views

Equivalent of RadialOutside for Graph VertexLabels

I'm creating a circular graph and want the labels to be placed on the outside of the vertices in a circular manner on the outside of the graph. I've been playing around with the ...
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5answers
362 views

Ordering the Boundary points of a Polygon

I feel like this should be simple, but I keep running into walls. Say someone gives you the coordinates of the vertices of a pentagon and the center point of the hexagon. Is there any way to get an ...
4
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1answer
2k views

How can I draw the transition diagram of a Markov chain?

I apologize for my heaviness as I am a Mathematica novice. Is there a kind soul who can tell me how to draw diagrams like those shown on page 158, 160 and 161 of this document.Chaine de Markov I ...
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2answers
102 views

Using VertexDelete to remove vertices by degree

I am trying to remove vertices that have degree less than 2, but I think I am missing something basic. I was hoping that I could use: ...
4
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1answer
211 views

Is it possible to draw a curved edge between two vertexes of a graph? [duplicate]

The following code generates a graph. ...
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2answers
344 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 ...
4
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2answers
184 views

GraphPlot with black edges no rendering function

Is there any way to make the edges of a GraphPlot black without tediously writing out a long "EdgeRenderingFunction"? I guess you could ask the same kind of question about vertex labeling. For ...
4
votes
3answers
963 views

Minimum spanning Tree from a weighted adjacency graph

Note: Cross-posted at http://community.wolfram.com/groups/-/m/t/137658?p_p_auth=8QnKtT9I I have a really big graph, 40x40. Here is my code ...
4
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2answers
179 views

HighlightGraph with style

In this picture you see a graph. The shortest path between vertex 5 and vertex 3 is highlighted in red. Instead I want blue highlighted edges of thickness 10. ...
4
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2answers
2k views

How do I plot a solution of a differential equation?

I am having trouble generating a plot for a solution to my differential equations. I always end up with just blank axes. ...
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2answers
323 views

Combinatorica: Girth[] and FindCycle[] disagreement

Warning: run the following code in a fresh Mma session, as some symbols could be shadowed (depending on your Mma version) While trying to answer this question, I fell into the following: ...
4
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2answers
223 views

Odd behavior of GridGraph and DirectedEdges

For some reason the option DirectedEdges->True, albeit working internally with grid graph, does not appear in the visualisation for 1D and 2D graphs. It also ...