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

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21
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1answer
1k views

Is there a way to convert an image into a Graph?

I'm trying to convert an image with several overlapping dots into a Graph. The goal is to be able to derive the Kirchhoff matrix for the randomly created "network ...
2
votes
2answers
142 views

Is it possible to use PropertyValue to modify properties of Graph objects in a list?

This post can be seen as a follow up to Property assignment on a graph vertex using PropertyValue does not work inside a function. I have defined a function: ...
2
votes
0answers
187 views

How to predict some constant number of values with NeuralNetworks

Example: << NeuralNetworks` data = {Sin[#]} & /@ Range[0, 4 Pi, 0.5]; learn = data[[1 ;; 15]]; Now, lets fit our neural network: ...
11
votes
2answers
775 views

Creating a graph with variable size of vertices and variable thickness of edges

I'm trying to create a graph to represent transitions between different states of a system. I would like to represent the time the systems spent in a state with the size of the vertex and the ...
18
votes
1answer
710 views

Graph vs GraphPlot

What is the difference (in purpose) between Graph and GraphPlot? Which function is bested suited to which tasks? Background: I ...
7
votes
2answers
479 views

Controlling TreePlot (and GraphPlot) layout issue

A continuing battle with Mathematica involves graphics heavy with text labels. For example, the following expression renders so that the "Lifecycle properties..." ...
6
votes
2answers
216 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 ...
10
votes
1answer
180 views

Issue with PathGraph

I am having a strange issue with PathGraph. Executing PathGraph[{a, b, c}] or ...
5
votes
0answers
225 views

How to compute the genus of a Graph?

What's the simplest way to compute the genus of a graph using Mathematica? I have looked for a Genus function (even in the ...
6
votes
1answer
137 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, ...
17
votes
4answers
763 views

How can I replace bi-directional DirectedEdge pairs in a Graph with a single UndirectedEdge?

The Cayley graphs produced by Mathematica 8.0's CayleyGraph function represent actions that are their own inverses in an unconventional way: rather than using a ...
10
votes
2answers
381 views

Select a directed SubGraph without sinks and sources

Consider the following problem: Assume you have a large list of directed edges, that constitute a large graph. I would like to provide an initial subset of vertices and I need to know which additional ...
11
votes
1answer
280 views

Ulam's Spiral with Opperman's diagonals (quarter-squares)

First we craft a function to return the quadrant boundary based on Oppermann's Conjecture a[n_] := (Mod[n, 2] + n^2 + 2 n)/4 Then we create a few lists ...
5
votes
3answers
262 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: ...
8
votes
2answers
278 views

How do I convert this Nicomachus's Triangle to one with edges?

I want to put edges on this Nicomachus's Triangle r = 7; t = Table[2^(n - k) 3^k, {n, 0, r}, {k, 0, n}]; ColumnForm[t, Center] Is there an easy way to do this? ...
10
votes
2answers
259 views

Using Gather to rearrange my data

I have a list of elements: {{1, 2}, {1, 5}, {2, 6}, {3, 7}, {4, 8}, {5, 6}, {5, 9}, {9, 13}, {10,11}, {11, 12}, {11, 15}, {15, 16}} I have to divide it into ...
6
votes
2answers
261 views

Efficient setting of properties of multiple vertices in Graph

The functions SetProperty and PropertyValue can only set a single property of a single vertex, as far as I know. How do I set a ...
6
votes
1answer
128 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 ...
13
votes
3answers
449 views

Determining all possible traversals of a tree

I have a list: B={423, {{53, {39, 65, 423}}, {66, {67, 81, 423}}, {424, {25, 40, 423}}}}; This list can be visualized as a tree using ...
7
votes
2answers
354 views

HighlightGraph with different styles

I want to highlight two different directed paths on a graph with two different style. I am using the following two code snippets: ...
4
votes
1answer
205 views

Removing edge weights from a Graph

How can I remove EdgeWeights from a Graph without affecting any other properties of the graph? Let's construct a graph with ...
5
votes
3answers
582 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 ...
16
votes
2answers
643 views

Graph layout on a grid

Is it possible for Mathematica to layout a graph so that the connections lie on a grid? Furthermore, for graphs with multiple edges per vertex, is it possible to specify the location on the vertex ...
40
votes
2answers
9k views

How can I use Mathematica's graph functions to cheat at Boggle?

This question is inspired by a Stack Overflow question that I decided to solve using Mathematica. In addition to Mathematica, I thought I'd use some of the new version's graph-related functionality, ...
4
votes
1answer
1k views

Is it possible to generate a Hasse Diagram for a defined relation?

I'm looking for a way to create a Hasse Diagram from a given partial order binary relation. The relation will be given explicitly, for example: ...
17
votes
1answer
319 views

How to visualize large graphs with directed edge bundling

I'm wondering if anyone has implemented edge bundled graph plotting? http://www.win.tue.nl/~dholten/papers/forcebundles_eurovis.pdf
3
votes
3answers
706 views

How to draw a directed graph with arrows showing vertically from bottom to top

If I have a directed graph, how can I draw it with arrows pointing vertically from bottom to top, like showing a class inheritance pattern in OOP(object oriented programming)?
6
votes
2answers
213 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. ...
14
votes
1answer
357 views

When to use built-in Graph/GraphPlot vs. Combinatorica

What are the pros and cons of using built-in Graph/GraphPlot (and related) types vs. types in the Combinatorica package?
3
votes
1answer
307 views

Combinatorica Graph from Edge List

Can someone provide an example of a Combinatorica-based graph which uses ShowGraph and Graph and takes in an explicitly defined list of edges (not some auto-generated graph). I have not been able to ...
3
votes
1answer
180 views

How do I get VertexList to work directly on older graphs defined using rules?

In MMA 8, it seems that sometimes VertexList will work with rule-based graphs without needing GraphUtilities and at other times it won't. Once it starts working, it ...
6
votes
3answers
133 views
12
votes
1answer
512 views

Drawing Graph Products

I need to draw graphs that are Cartesian products of 2 graphs. I need them to look like this: . So each copy of the factors can have LinearEmbedding, but the whole ...
15
votes
1answer
390 views

Need tips on improving this directed graph

First we define a function that returns the least odd prime factor. lopf[n_] := FactorInteger[n][[2, 1]] Then we craft a routine that performs the 3x+1 steps ...
12
votes
2answers
305 views

Comfortable Edge Labeling of Undirected Graph

I'm working on a program that finds special [called "interval"] edge-colorings for graphs. Output is as follows: ...
13
votes
3answers
570 views

How to find all vertices reachable from a start vertex following directed edges?

How to find all vertices reachable from a given start vertex following directed edges, in a cyclic directed graph given as ...
5
votes
1answer
347 views

Visualizing the output of a Voronoi diagram computation

I need to plot a graph (to be specific: Fortune Algorithm output) with given vertex coordinates and a few unconnected vertices. I am thinking of using Mathematica for that. ...
10
votes
1answer
141 views

Figuring out how AbsoluteOptions works with Graphs

I am puzzled by how AbsoluteOptions works with Graph objects. I would have expected that one could use it to obtain all the ...
13
votes
4answers
404 views

How to recompute the layout of a Graph?

I asked a question about changing Graph properties in a similar way to how Show can change ...
7
votes
2answers
188 views

Graph does not accept Property Options

My question is concerned with the Graph functionality, which was newly implemented in Mathematica 8. I already used GraphPlot ...
16
votes
3answers
2k views

How to get graph layout that reflects edge weights?

My heart soared to discover that Mathematica 8 offers support for specifying a weighted adjacency matrix in WeightedAdjacencyGraph. But it seems that, regardless of the weights between edges, the ...
5
votes
2answers
490 views

Coloring edges in GraphPlot

I'm a little stuck with graph drawing part of my research — I can't use the Graph function for plotting my graphs, because my graph is a multi-graph. ...
5
votes
0answers
69 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) ...
5
votes
3answers
353 views

How to display edge labels above edges?

The following code shows that edge labels "cover" edges in GraphPlot3D ...
12
votes
1answer
719 views

How to divide a graph into connected components?

Suppose I have some edges: edges = {1 -> 2, 2 -> 3, 3 -> 1, 4 -> 5, 3 -> 6, 7 -> 8, 8 -> 9, 8 -> 10}; And I make a graph: ...
5
votes
3answers
302 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 ...
3
votes
0answers
172 views

Is it possible to manipulate graphs by hand? [duplicate]

Possible Duplicate: Generating graphs interactively (GUI) If I plot a graph, is it possible for me to manipulate the vertices such that when I move them, their attached edges will follow. ...
25
votes
3answers
2k views

Finding all shortest paths between two vertices

The built-in FindShortestPath and GraphDistance functions find the shortest path between two particular vertices in a graph. I ...
21
votes
3answers
707 views

Finding a “not-shortest” path between two vertices

In designing a routine for making a simple three dimensional (5x5x5) labyrinth, I realized that my solutions (a solution is a labyrinth includes a single path from {1, 1, 1} to {5, 5, 5} in a 5 x5x5 ...
4
votes
1answer
216 views