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

learn more… | top users | synonyms (2)

6
votes
2answers
245 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
395 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
390 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
230 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
162 views
12
votes
1answer
666 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
433 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
363 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: ...
17
votes
4answers
735 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 ...
7
votes
3answers
626 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
165 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
468 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
207 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 ...
18
votes
3answers
3k 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 ...
7
votes
2answers
736 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
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) ...
5
votes
3answers
495 views

How to display edge labels above edges?

The following code shows that edge labels "cover" edges in GraphPlot3D ...
12
votes
1answer
1k 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: ...
6
votes
3answers
454 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
178 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
4answers
4k 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 ...
24
votes
4answers
1k 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
236 views
18
votes
1answer
198 views

Is UndirectedEdge[a,b] the same edge as UndirectedEdge[b,a]?

Is UndirectedEdge[a,b] the same edge as UndirectedEdge[b,a]? Then please consider this. ...
8
votes
2answers
259 views

Cases[data,Colon[key,_]] vs. Cases[data,key:_] toward XPath, XQuery

Exploring methods to index and search tree-structured key:value pairs via named-entity index (key paths) as opposed to Position-based indexing. Using Rule as ...
9
votes
1answer
697 views

When using GraphPlot with an adjacency matrix, how can I make Mathematica draw exactly one self loop for any non-zero weight?

I have tried using the option MultiedgeStyle->None, but apparently Mathematica doesn't treat self loops in the same way it treats edges. For example, I find ...
10
votes
2answers
197 views

NumberOfSpanningTrees command not working correctly

I am attempting to use the Combinatorica NumberOfSpanningTrees command for all n-cycle graphs from 3 to 30. I am trying to get a ...
7
votes
2answers
512 views

Edge problems in a directed graph

I want to create the following two graphs. So far I tried the following Code ...
12
votes
2answers
1k views

Simple algorithm to find cycles in edge list

I have the edge list of an undirected graph which consists of disjoint "cycles" only. Example: {{1, 2}, {2, 3}, {3, 4}, {4, 1}, {5, 6}, {6, 7}, {7, 5}} Each ...
3
votes
1answer
217 views

Forcing a graph not to resize

This code: ...
4
votes
1answer
208 views

What's the most intelligent way to store the information of a selfmade graph?

I have a very long list of element, say $a1,a2, a3$,..., and they are all connected in that each is the child of many parents. E.g. $a74$ is associated with $a2,a55,a71$, and also contains ...
12
votes
2answers
368 views

Listing subgraphs of G isomorphic to SubG

If I have an undirected graph G, how could I write a function in Mathematica to obtain a list of subgraphs of G that are isomorphic to some other undirected graph SubG? I'd like to learn how to ...
21
votes
2answers
2k views

Cycles of length N in a graph

If I have an undirected graph represented with an adjacency matrix, how can I find all the subgraphs which are a cycle of length N? I don't really know the math nor the programming language well, so ...
23
votes
3answers
1k views

Generating graphs interactively (GUI)

I want to create graphs interactively using a GUI. I thought of using a ClickPane[] environment. The code I have (in part borrowed from the Documentation) works ...
19
votes
2answers
394 views

Packed Graph or GraphPlot output with non-square layout?

Graph or GraphPlot produce square layouts for disconnected graphs: Graph[Table[i -> Mod[i^3, 100], {i, 1, 100}]] I´d like to get a rectangular layout with ...
2
votes
2answers
500 views

How to impose custom style to the edges of a graph

We construct a graph as the following. ...
4
votes
1answer
181 views

HITS centrality

I want the centrality measure of a particular vertex in my graph, and for Closeness, Betweenness and Degree centralities I have been using : ...
6
votes
2answers
252 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 ...
2
votes
1answer
163 views

VertexLabelStyle not found in Mathematica 8.0.0.0

I tried to use VertexLabelStyle, but seemed not recognized in my system with version number 8.0.0.0. Is this expected or I have missed something? From the online ...
8
votes
1answer
734 views

How to add vertex/edge labels to existing graph

If I have already created a graph using Graph. Later, I want to add to the graph some vertex and/or edge labels, how can I do that? Thank you.
4
votes
1answer
408 views

Get the neighboring vertices and incident edges from a vertex in a graph

I need to get the neighboring vertices and incident edges from a vertex in a graph. I assume NeighborhoodVertices can be used for the former. Anything better? Or ...
3
votes
1answer
846 views

How to write a function to add edges or vertex to a graph

I need to add either a vertex or an edge to a graph, and also sometimes, vertices or edges, or a mixture of the two. How to write a function for this?
16
votes
1answer
383 views

Convert GraphPlot[]s with many nodes into something that's human-understandable

This is more of an abstract/creative problem. I think everyone who has played around with GraphPlot, ended up with an image that looks like this, at least once in ...
10
votes
3answers
824 views

How to plot layered graphs?

Given a directed acyclic graph, there is always a possibility to plot the graph as layers, where nodes always send edges into one direction (usually down), to successive layers, and never backwards. ...
5
votes
3answers
331 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 ...
21
votes
2answers
2k views

How to plot planar graphs as such?

A planar graph is a graph that can be drawn in the plane such that no two edges cross. For example, the graph ...
6
votes
1answer
344 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 ...
7
votes
1answer
986 views

Mathematica: Label specific vertices in GraphPlot

How can I label particular vertices in GraphPlot? And have the arrows space out accordingly, for the width of the label? I have Mathematica 7, but I think this question applies to all versions. ...
9
votes
4answers
489 views

Show path with arrows in a matrix

I have a matrix, for example, 5x5 matrix Partition[Range[25], 5]. And I am given a list, for example: ...
15
votes
6answers
456 views

How can I remove B -> A from a list if A -> B is in the list?

I have a list of transformations like this: list = {"A" -> "B", "B" -> "A", "C" -> "D"} As this is used to plot an undirected graph with ...