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

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2
votes
1answer
51 views

Increasing the font size in the Vertexlabels of GraphPlot

I have the following code and corresponding output: GraphPlot[Table[i -> Mod[3^i, 5], {i, 20}], VertexLabeling -> True] I wish to do two things: 1) ...
1
vote
1answer
35 views

Display options for GraphData output [duplicate]

How can the display of graphs using GraphData be customized? For example, how can we customize the vertex style, color, edge thickness of the output to...
9
votes
1answer
76 views

Cannot set VertexCoordinates twice in a Graph. Workaround?

Versions 10.0-10.2 seem to have a bug when trying to set VertexCoordinates twice on a graph (version 9.0 is fine). Can you confirm it? What is a good workaround ...
5
votes
1answer
236 views

Adjacency matrix from image file of plane map

I have image files (PNG format) of plane maps of regions delimited by black borders I would like Mathematica to compute the associated adjacency matrix for the contiguous regions in these maps. ...
0
votes
0answers
63 views

adjacency matrix with directed graph connected nodes

I was trying to plot a 9x9 adjacency matrices which produce a useless directed graph. Codes for that I used: ...
0
votes
0answers
118 views

ViewVector requires click before behaving with Graph3D (Also, viewing 3D subgraph “head on.”)

I want to produce 3D subgraphs that looks "head on" at the remaining vertices, held in their original positions via VertexCoordinates. The default viewpoint is not ...
2
votes
0answers
37 views

Algorithm to determine if two colored graphs are isomorphic? [duplicate]

I have two (vertex-)colored graphs. I want to determine if they are isomorphic, with the condition that the isomorphism respects the colors of the vertices. Moreover, I want the algorithm to output ...
3
votes
1answer
103 views

Multiple colors on a single graph edge?

Is there any way to put two colors on one single graph edge? For example, I want to highlight two cyclic paths (red and blue). But, if I put the two colorings into one image, it does not work as I ...
1
vote
0answers
112 views

GraphDistance gives incorrect result in weighted multigraph [closed]

Bug introduced in 10.0 and persisting through 10.3 Multigraph support was introduced in 10.0 There are bugs in Graph on Mathematica 10.1. For example, ...
5
votes
2answers
162 views

How to show the direction of highlighted path in graph

I am trying to show the direction of FindHamiltonianPath on the Graph. ...
6
votes
1answer
221 views

Vertex Order of Graph

Given a graph, I want to find the shortest distance between each pair of vertices: ...
6
votes
0answers
103 views

Issues adding properties to multigraph

Unsupported Functionality (loosely, a bug) Mathematica (as of 10.4.1) does not support multi-graph where edge properties vary between two nodes that share multiple edges. Although this is not ...
3
votes
2answers
93 views

How to specify different colors for edges going between the same two vertices in Graph?

Here is an example: edge1 = Property[1 -> 2, EdgeStyle -> Red]; edge2 = Property[1 -> 2, EdgeStyle -> Blue]; Graph[{edge1, edge2}] This does not ...
1
vote
1answer
61 views

Unexpected AdjacencyMatrix output [duplicate]

I have a directed graph with this Edgelist defined as follow: ...
2
votes
2answers
84 views

How-to let user define a set of VertexCoordinates in a Graph

Here is a simple code I wrote to visualize what I am trying to achieve: C.1 ...
1
vote
1answer
138 views

How do I customize vertex label texts in tree plot correctly?

By the following code TreeGraph[{1, 2, 3}, {1 -> 2, 1 -> 3}, VertexLabels -> {"a", "b", "b"}] I get . This is incorrect. I need "a" to label the vertex ...
2
votes
2answers
80 views

Recursive graph expansion and rewiring

I want to take this graph and convert it into this graph by repeatedly substituting each of its nodes according to this rule After loading the initial graph and the substitution rule <...
6
votes
1answer
242 views

Calculate dual graph of planar Graphics map

This diagram from a Wikipedia article illustrates what I hope to accomplish in Mathematica: I have a planar map in Graphics format. Here are two very simple ...
7
votes
1answer
122 views

How to extract a Graph[] from an image?

This graph (as a picture) is given below: I am wondering rather than setting up this network graph using Mathematica syntax such as PathGraph,...
1
vote
2answers
161 views

Styling the edges of a graph according to the multiplicities of the edges

I used the following code to make a simple triangle, in which the nodes have different effects each other: ...
1
vote
1answer
69 views

calculate relationship between cause and effect (rows/columns/delta etc.) on tableform

I tried to enter this Excel (on the right of the picture) information to program. following these codes has been used: ...
6
votes
2answers
120 views

Delete vertices of degree 2 and rewire graph

I want to delete all vertices of degree 2 from a graph and rewire it. Given a graph like graphA, I want to obtain graphB. ...
12
votes
0answers
180 views

A question about weighted graphs

Bug introduced in 8.0 or earlier and persisting through 10.3 I need create a weighted graph with given data. Number of nodes: $53$ $\quad$ Number of edges: $91$ ...
1
vote
1answer
98 views

How to find a cycle with a property in a graph

Let's have a graph with this edge list: edgelist = {s -> 1, s -> 2, 1 -> 3, 2 -> 1, 2 -> 4, 3 -> 2, 3 -> t, 4 -> 3, 4 -> t}; I want ...
5
votes
1answer
109 views

How to create a MorphologicalGraph from MorphologicalBranchPoints

I want to select the morphological branch points of a thinned image to create a MorphologicalGraph like the one obtained by Pruning. I want to avoid the pruning step. How can I delete from the ...
0
votes
1answer
64 views

How to check if (u,v) and (v,u) edges are in a given directed graph

I have a graph and i want a module to run through all the edges of this graph and check whether (u,v) edge is in this graph and (v,u) edge is in another given graph.
2
votes
1answer
101 views

Visualisation of feedback loops in a directed graph

Here are the nodes (vertices) of my graph: ...
0
votes
0answers
36 views

Weighted graph vizualization [duplicate]

Is it possible to visualize a weighted graph, so lines on screen would reflect weight? I.e., be longer, or shorter depending on edge weight? Slight OT: which graph visualising libraries/tools can do ...
3
votes
2answers
127 views

Coloring network edges by weight using GraphPlot

Following up on a previous question about how to color the nodes (vertices) of a network (graph) according to a color scaling of a property of those nodes, I'm now asking basically the same thing ...
2
votes
2answers
75 views

DiscreteMarkovProcess: labelling of states

Related, but it seems like the respondents there misunderstood the question. The following errors as DiscreteMarkovProcess::invsm: ...
14
votes
1answer
162 views

IsomorphicGraphQ fails to recognize that two empty graphs are identical

Bug introduced in 9.0.1 or earlier and persisting through 10.4.0 Consider the following two graphs: ...
0
votes
1answer
46 views

How to perform operations with vertices from any edge on a Graph object

I'm trying to get the vertices from an large list of edges on a Graph object in Mathematica 10. I need to operate them, adding, substracting dividing. As an ...
0
votes
0answers
59 views

Why does (Layered)GraphPlot lose labels and renumber vertices?

I define a graph of numbers as vertices, but also labeled, like g=Graph[{Labeled[1 \[DirectedEdge] 5, "text1"]…},VertexLabels -> {79 -> "text2",…}]. This is ...
2
votes
1answer
70 views

Count graphs with fixed number of vertices incluing isomorphisms [closed]

I'm trying to use the listgraph function in the Combinatorica package: Needs["Combinatorica`"] g = ListGraphs[5]; ShowGraph /@ g However, it only returns all the ...
8
votes
2answers
224 views

Efficient solution for a discrete assignment problem with pairwise costs

Let's consider a simple graph with N vertices, and a corresponding set of N items. The goal of the problem is to assign every item to a vertex on the graph so that sum of a per-edge (that is item-...
2
votes
2answers
75 views

Network Graph: show highly connected components

I want to create a network graph without the small subgraphs which are disconnected from the big network graph. Suppose I want to visualize the edgelist: ...
5
votes
1answer
191 views

Arbitrary shape GridGraph

There is a function GridGraph that generates a finite square lattice graph. Is there a way to make a generalized solution (e.g. with hexagons, or triangles instead of squares)? To put it in more ...
2
votes
0answers
99 views

Graph, overlapping vertexlabels

The graph I create is based on more then 1000 different word-combinations. A example looks like this: text = {{word, word1}, {word1, word2}, {word1, word3}, {word,word4}, {word,word5}, {word,...
1
vote
1answer
47 views

Can I rely on the ordering of the adjacency matrix? [closed]

Suppose I have created a Graph[{1,2..n}, {1->3, etc}], and I take the adjacency matrix of that graph. Can I rely on the fact that the i-th entry in the graph is the i-th node in the matrix? Or maybe ...
4
votes
1answer
287 views

Why don't the arrowheads show for this directed graph?

Bug introduced in version 9.0 or earlier and fixed in 10.3 It's very weird, but the first graph is shown as undirected (dots connected by lines, not arrows. The second is shown as directed, with ...
3
votes
1answer
62 views

How can I get the vertex labels of an existing graph?

For example, if there is a graph g = CompleteGraph[5, VertexLabels -> {1 -> "v1", 2 -> "v2", 3 -> "v3", 4 -> "v4", 5 -> "v5"}] How can I later ...
1
vote
1answer
91 views

Compute complete graph and make minimum spanning tree

I'd like to plot a complete Graph and then compute the Minimum spanning tree of it. I already can make a complete graph out of a list that countrydata gives me: ...
4
votes
2answers
111 views

Iterative Tree Plot for the Sum of an Integer's Digits Squared

I am trying to make a graph that depicts integers<100 mapping to the sum of their digits squared. I can do this for one iteration, but I don't know how to do it for more than one, or until the new ...
4
votes
2answers
66 views

Graph: vary color/length vertextlabels based on frequency

In this example I use a small network of 5 words. ...
1
vote
2answers
123 views

What is the correct way to assign and use properties of vertices in graphs?

I'm using Mathematica 10, but I'm having a hard time getting it to do anything useful for network analysis because I'm having a hard time working with node properties and analyzing the graph by its ...
6
votes
1answer
99 views

Slow-down encountered for RandomChoice in large lists

I was wondering if anyone could help me to speed up this code snippet which creates simple (sparse) networks by preferential attachment. The algorithm adds a vertex and an edge each time interval. ...
6
votes
0answers
72 views

Functionality of FindMaximumFlow

I know that the superseeded function NetworkFlow (needs Combinatorica) uses Goldberg-Tarjan's Push-Relabel-Algorithm but i cant find any information on Mathematica's built-in-function (...
1
vote
0answers
49 views

reset the value of a variable [closed]

Folks, I have a problem in populating a matrix without overriding the values. After performing computations for various values for j, I want to store these values in following matrix. Here is the code:...