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

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6
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3answers
734 views

Random Geometric Graphs

I'm trying to implement an application which uses random geometric graphs in Mathematica, but it seems Mathematica lacks the functionality. I need the following functionalities: Generate a set of ...
6
votes
2answers
356 views
6
votes
4answers
3k views

How to generate random directed connected graph?

How to generate random directed connected graph? I need to create graph which will pass: ConnectedGraphQ[^]
6
votes
2answers
2k views

Eigenvalue / Eigenvector Calculation

I'm currently trying to compute the three smallest eigenvectors for a 34 by 34 matrix. While I was expecting this to take some time, Mathematica has been running for the past 3 hours, which seems ...
6
votes
2answers
228 views

How to make each node of a graph a button?

A newbie question this one - MMA help seems to suggest it would be possible to place a button on ( or have a button be ) each node of graph, labelled with the name of said node. I have no idea where ...
6
votes
3answers
719 views

Graph adjacency matrix with unconnected nodes

I am trying to display a series of 9x9 adjacency matrices which represent directed graphs on a 3x3 grid. The issue I am running up against is this (compounded by that fact that I don't really know how ...
6
votes
1answer
144 views

Replacing graph nodes with matrices

I would like to label a graph with matrices. Suppose the graph is simple: And I have an array mats that contains the labels for vertices 1,2,3,4 (these are just random 0-1 matrices; ignore the ...
6
votes
1answer
243 views

Coloring edges of a graph according to their weight?

What's the simplest way to plot a graph with weighted edges, such that the color of the edge corresponds to the weight of the edge?
6
votes
2answers
145 views

Why the Mouse dragging response not as smooth as Locator

I am experimenting to use MouseDragged eventhandler to change the vertices positions of a triangle, it works, but not as smooth as using Locators. Is this the ...
6
votes
3answers
340 views

Flow in pipeline graph

I have pipeline directed graph which has one source and several sinks ...
6
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3answers
165 views
6
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3answers
467 views

How to extract edgeweights from a graph

I have a graph with weighted edges, and I'd like to obtain the edge weights of the edges in the graph. Is there a nicer way of doing this than getting the ...
6
votes
2answers
301 views

How to color edges of a graph which has multiple edges connecting certain vertices

I'm studying BIBD(Balanced Incomplete Block Design) and want to draw some graphs by coloring their blocks in different colors, respectively. A block is a collection of edges (or vertices). For ...
6
votes
2answers
351 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
1answer
610 views

How to turn a random graph into a matrix

I have constructed a random graph with Mathematica using the RandomGraph command. Now I would like to convert this graph to a matrix, but I don't know how. The ...
6
votes
4answers
193 views

Automatically convert pairs of directed edges to an undirected edge?

I have a directed graph, which for some pairs of vertices, has a directed edge between them in each direction. I would like to replace such pairs of directed edges between the same vertices but in ...
6
votes
1answer
718 views

How can I draw a polygon from a set of angles?

In recreational mathematics, polytans are polygons formed by edge-connecting isosceles right triangles. Order-n polytans are those constructed from n such triangles. My question is this: Given a ...
6
votes
2answers
257 views

Truncate TreeForm to show only the top

For some expressions, TreeForm may grow very long. I'm only interested in the top levels of the expression. How can I get the tree form of only the first levels an ...
6
votes
1answer
175 views

Fractal dimension of a large networked molecular system

I am trying to determine the fractal dimension of this complex biomolecule (figure attached). Any clues as to how this can be done. In trying to determine this quantity, I wonder how its ...
6
votes
1answer
227 views

Generating a (random) 2-dimensional cellular network

I want to generate a network of random cells like the following picture: The general idea is to generate some random points (x,y) as coordinate of a vertex and then randomly choose some of these ...
6
votes
3answers
366 views

Export Graph to PDF

I know that I exported Graphs to PDFs before but it doesn't seem to work any more. I tried K5 = GraphData[{"Complete", 5}] Export["K5.PDF", K5] And I get a PDF ...
6
votes
1answer
280 views

What algorithm is Mathematica 9 using for “SpectralEmbedding” of graphs?

When I specify that a graph should be realized using the "SpectralEmbedding" procedure, what paper / algorithm for spectral embedding is this based on? I was unable to find any documentation for ...
6
votes
1answer
248 views

How to view all graphs available in GraphData?

Is there a "gallery" view of all the graphs available in GraphData? I realize that some graphs may not lend themselves to such representation (e.g. some may have ...
6
votes
3answers
225 views

Enumerate the 1-factors (perfect matchings) of $K_n$

Introduction I would like to enumerate the 1-factors, or (near-)perfect matchings, of the complete graph Kn. The adjacency list representation for Kn is basically { (x, y) | 1 ≤ x < y ≤ n }. For ...
6
votes
1answer
967 views

Analysis of Facebook group

I am the admin of a Facebook group for our year at university and wanted to graph the members of the group like you can with your own friends so we can find the isolated people and get rid of them (as ...
6
votes
2answers
280 views

Flow/graph-based programming in Mathematica?

Is it possible in Mathematica to write a program inside a graph? For example if you have a bunch of different If[] statements that you need to embed within one ...
6
votes
2answers
248 views

Visualize the output of Trace in a tree structure

The output of Trace[expr] can be nicely represented as a tree, I guess. Here is an example trace. ...
6
votes
1answer
347 views

How to determine edgeweights from width of skeleton using MorphologicalGraph (or workaround)?

Background I'm trying to create a workaround for what seems to be a bug in MMA's graph functions related to edge weights: SO: How to Label Graph Edges with their weights According to MMA's ...
6
votes
1answer
228 views

Shortest polygonal path

I'd like to find the shortest distance between some points (every point must be visited), such as between these 3 points: ...
6
votes
1answer
132 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 ...
6
votes
1answer
563 views

(Efficiently) Generating graphs with vertex degree 3 for all vertices

I'm working on a graph theory problem, and given $n$ vertices, I would like to be able to generate all non-isomorphic connected graphs (not necessarily simple) with $n$ vertices, each having degree 3. ...
6
votes
2answers
272 views

How do I reorder vertices in a graph?

I have a directed acyclic graph $g$, and I'd like to re-order the vertices in this graph object such that when I call VertexList[myGraph] the vertices appear in ...
6
votes
1answer
162 views

Property assignment on a graph vertex using PropertyValue does not work inside a function

I created this function: AddStone[board_Graph, v_, s : white | black | empty] := PropertyValue[{board, v}, VertexState] = s This function should change the ...
6
votes
1answer
82 views

Setting PropertyValue for VertexWeight is not persistent

g = CompleteGraph[8, VertexSize -> Medium]; PropertyValue[{g, VertexList[g][[1]]}, VertexWeight] = 10; PropertyValue[g, VertexWeight] ...
6
votes
1answer
880 views

Ordering vertices with minimum Edge Crossing in Circular Graphs

Weighted and sorted Mathematica circular graphs are shown below. My question is how to reorder the vertices in such a way that they have minimum cuts (intersection of edges) while keeping the circular ...
6
votes
1answer
149 views

Vertices, their labels, and how to refer to them?

In the examples I have seen, graph vertices in Mathematica are usually explicit small integers. However, Wolfram documentation says that vertices can be any arbitrary expression (eg., george, x^2, ...
6
votes
1answer
312 views

Connect neighbouring points as list of segments in 2 D

Context I am interested in connecting neighboring points in 2/3D as list of segments. I am guessing this is something within the reach of graph theory, which is well implemented in mathematica. ...
6
votes
1answer
161 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: ...
6
votes
1answer
390 views

Interactive Graph Editing with Animation

I want to make a simple interactive user interface like this: Such that when the user clicks on the "Add Edge" button, the edge specified by from and to fiels is added to the graph. The new graph ...
6
votes
0answers
39 views

What system functions use VertexWeights?

EdgeWeights -> are used by a lot of functions, but I can't find any exposed usage for VertexWeights ->. I'm not asking ...
6
votes
0answers
96 views

HighlightGraph and Hyperlink

In the documentation of Mathematica it is mentioned that you can use Hyperlink and Tooltip as wrapper in a similar manner as ...
5
votes
3answers
608 views

Graph and Markov Chain

I have the following code: proc = DiscreteMarkovProcess[1, {{0.6, 0.4}, {0.3, 0.7}}] Graph[{"A", "E"}, proc, GraphStyle -> "DiagramBlue"] How can I 'force' ...
5
votes
3answers
666 views

How to create a planar graph from a set of random points

Question Given a set of points in the plane, how can you create a planar graph in the standard graph representation of Mathematica (version 9 or higher), from these points? Background A planar ...
5
votes
3answers
218 views

Enumerating all connected graphs with 9 vertices

The version of my Mathematica is 10. I generate a connected graph with 9 vertices, but find that it is not included in Mathematica. ...
5
votes
3answers
504 views

How to display edge labels above edges?

The following code shows that edge labels "cover" edges in GraphPlot3D ...
5
votes
2answers
163 views

Drawing a path which realises the diameter of the graph

So I enter a (0,1) adjacency matrix and I get the following graph: The diameter of this graph is 4. How can I ask that two vertices which realise this diameter be drawn with different filling ...
5
votes
4answers
101 views

Vertex styling in CommunityGraphPlot

Is there a way to change the colours of nodes within one community? Mathematica assigns vertex colours automatically to each community. However, I'd rather like to use my own colour set. ...
5
votes
2answers
125 views

Visualizing subgraphs while specifying the locations of vertexes

I would like to visualize separate connected components of a graph defined by data points lying in the two-dimensional plane by surrounding each connected component subgraph by a bounding curve. I ...
5
votes
3answers
181 views

StandardForm on Graph edges

The Graph command displays edge labels in TraditionalForm. I instead want to use ...
5
votes
3answers
200 views

Converting expressions to “edges” for use in TreePlot, Graph

This question is similar to this: Nested list to graph. How to "flatten" an arbitrary expression, eg expr = a[b[c, d[e][f], g], h] to a list of key-value pairs ...