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
2answers
223 views

Can I solve this graph theory problem with Mathematica?

Internet browsing I came across this problem, as can be solved using Mathematica. Edit: The image says: Place the following numbers 1,2,3,4,5,6,7 in the following diagram (all), without repeating any ...
1
vote
1answer
70 views

Export and Import a list of graphs?

I want to export a list of graphs that come as output to my program. However, I tried exporting all the graphs as graphs using Map and an Export statement with "graph.gml" statement, but got an error. ...
1
vote
1answer
81 views

VertexLabels, EdgeLabels and the direction of the arrows on a directed graph

I want to have three network types. My plan is to put them together in a figure file via marking them with (a) (b) and (c). The figures that I want to have, have some problems. Here is my code ...
1
vote
1answer
61 views

Is there a way to combine VertexLabeling->True and VertexLabels/Tooltip in TreePlot?

Basically, I'm trying to make Mathematica give me a tree with names inside the rectangles like so: ...while also having the properties of VertexLabels or Tooltip, which lets me place my mouse over ...
10
votes
1answer
295 views

Is there a function to generate a minimal clique cover?

This is a graph problem known as the "Clique Edge Cover" or "Intersection Number" problem, and the goal is to find, from a given graph like $E=\{\{a,b\},\{a,c\},\{b,c\},\{b,d\},\{c,d\}\}$ and ...
1
vote
0answers
105 views

Draw mesh edge / map a graph to a mesh

I am doing a "force density" method to generate a mesh under certain load. The original mesh is like this: Then, I generate a IncidenceMatrix from the graph for further matrix transformation and ...
0
votes
2answers
124 views

Random geometrical graph generation

I would like to generate a random graph on $[0,1]^2$. Each node is connected to one other if the distance between two nodes is say 1/4 or less. Here is an example with 50 nodes and 200 edges I would ...
4
votes
1answer
441 views

Something interesting about Pi, but something seems amiss

I saw something interesting about text-analysis - bigrams - in Basic Text Analysis in Mathematica I wondered how the bigrams of Pi's digits might appear. As expected, take enough terms and every ...
0
votes
2answers
101 views

Normalize centrality measures

How I can normalise centrality measures? Can I use Normalize function? I give example of unnormalized measures ...
1
vote
0answers
58 views

Successive addition or deletion of vertices (or edges) in graph

I am trying to perform a kind of dynamic graph simulation where vertices and edges of graph are added and deleted according to the current state of the graph at each time step. I know that there are ...
4
votes
1answer
197 views

VertexRenderingFunction (or EdgeRenderingFunction) with movable nodes?

In GraphPlot, I'd like to use VertexRenderingFunction (VRF) and have the resulting object behave the same way under dragging verticies as it does when I do not use VRF. The same issue occurs for ...
0
votes
0answers
50 views

Trying to write a program to find an approximate harmonic function on a given graph using relation method

So given an undirected graph with two vertices that have fixed values assigned to them, a harmonic function is a function that assigns values to all other vertices such that the value assigned to each ...
0
votes
1answer
58 views

EdgeRenderingFunction For 2 Vertices in a Loop

Assume there is a set of rules: set = {"A" -> "B", "B" -> "A", "B" -> "C", "C" -> "D", "D" -> "A", "C" -> "C"}; which we want to graph using ...
1
vote
0answers
52 views

What do the default shapes/colors in DiscreteMarkovProcess Graph mean?

In making markov chains, I know how to do that, but I am curious as to what the different colors, and shapes of the vertexes in the graph output mean. as example; ...
2
votes
1answer
268 views

LayeredGraphPlot Vertex Spacing / Edge Length

For anyone who has used LayeredGraphPlot (Mma v9), you have probably seen that the vertex spacing is consistent throughout, that vertices have the same minimum unit ...
2
votes
2answers
60 views

Efficiently or Elegantly construct linear graph list from vertex pairs

I am processing MRP data, with BOM relations as pairs of part number strings. I want to construct lists that represent the linear graphs defined by these pairs. Here is some code to generate random ...
1
vote
0answers
22 views

FindIndependentEdgeSet behaves differently in v9 and v10

The following code gets different output in v9 and v10. ...
5
votes
2answers
189 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 ...
4
votes
2answers
88 views

Color edges of a multigraph when there are parallel edges using Graph[] and EdgeStyle

This a related question to : How can I display a multigraph with different colored edges? However I'm not using GraphPlot. Instead I'm using Graph and EdgeStyle attribute. Take this graph : How can ...
4
votes
2answers
207 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 ...
1
vote
1answer
81 views

LayeredGraphPlot: how to specify edge endpoints?

What directive within the LayeredGraphPlot command specifies where the edges attach to vertices? For example, instead of the left output below, I'd like to have the right one. ...
7
votes
4answers
273 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 ...
0
votes
0answers
36 views

Error with AppendTo [duplicate]

I am trying to write a function that builds a graph, or - better said - adds a layer of leaves to a pre-existing graph. Basically, I hand to the function three lists. ...
0
votes
0answers
45 views

Draw a single disconnected vertex [duplicate]

I am just started using Mathematica. I am trying to split my graph into two sets. 1. How does Mathematica split the graph into 2 subgraphs (connected or disconnected)? 2. How can I draw a graph with ...
2
votes
1answer
60 views

`TransitiveClosureGraph` doesn't return self-loops for nodes that are in a cycle

This is from boost library documentation: The transitive closure of a graph G = (V,E) is a graph G* = (V,E*) such that E* contains an edge (u,v) if and only if G contains a path (of at least ...
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
3answers
262 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]. ...
5
votes
4answers
118 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. ...
22
votes
1answer
418 views

Visual representation of a Ranking over time (image provided)

[Disclaimer: I initially posted this question on stackOverflow 2 months ago and think it might be better suited for this forum (link to original question)] The graph below shows a ranking of ...
0
votes
1answer
43 views

How to query W|A, to get a list of asymmetric, bicubic and $3$-edge colorable graphs? [closed]

I'm interested in finding graphs with certain properties, like the smallest cubic bipartite asymmetric graph. While working on a related graph-theoretic problem, concerning edge-colrings, I came along ...
1
vote
2answers
72 views

Insert an element to AdjacencyGraph

I'm not able to insert an element to mine AdjacencyGraph. I suppose that i should modify my AdjcencyMatrix: ...
4
votes
2answers
149 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: ...
1
vote
0answers
52 views

Purpose of VertexWeight

I am trying to partition a graph into partitions of equal weight (on the vertex). I looked at the documentation, and found VertexWeight, which seems to attach a weight to a vertex. In the details, ...
9
votes
3answers
356 views

Label multiple edges between same vertices

I have a simple graph with multiple edges between two vertices, say: Graph[{ Labeled[a -> b, "A"], Labeled[a -> b, "B"] }] Unfortunately, Mathematica ...
3
votes
1answer
76 views

Change group generators?

I want to make Cayley graphs for the same group, but with different generators. Is there any way to represent a group, besides a cumbersome permutation representation or using the default Mathematica ...
2
votes
1answer
317 views

How to implement the directed Barabasi-Albert algorithm in Mathematica?

Does anyone know how to implement an efficient version of the [directed Barabasi-Albert algorithm][1] in Mathematica that scales until hundred of thousands nodes? The directed network mechanism is ...
3
votes
1answer
76 views
17
votes
4answers
879 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 ...
1
vote
1answer
78 views

How to insert Tooltip into incidence plot?

I'm trying to make a graph using a file .NET extracted from a file .CSV and to make tooltiped the vertices' labels. Initially I ...
3
votes
2answers
102 views

IsomorphicGraphQ giving an error when the graphs contain multi-edges

If I run IsomorphicGraphQ on the following graphs, I get an error I don't understand: ...
2
votes
1answer
54 views

AdjacencyList of DirectedEdges in Graph ignore edge direction

I have a simple tree graph with directed edges: In: AdjacencyList[Graph[{a -> b, a -> c, b -> d, b -> e}], b] Out: {a, d, e} I wonder how I can ...
2
votes
1answer
66 views

Specifying the style of edges in directed graphs [closed]

How do I specify the style of individual edges in a directed graph (in Mathematica version 9)? Consider maybe this ...
0
votes
0answers
62 views

Is it possible to use EdgeCapacity in FindMinimumCostFlow?

I'm having trouble getting the EdgeCapacity feature in FindMinimumCostFlow to work. I have attached a simple example. We have a simple graph of four vertices. There are two paths from the "source" ...
0
votes
1answer
63 views

FindCycle not working as expected for multigraph

Say I have a simple multigraph like so: edges = {DirectedEdge[a, b], DirectedEdge[b, c], DirectedEdge[c, a]}; g = Graph[Join[edges, edges]] ...
1
vote
0answers
40 views

Export format for graphs loses type information?

I have a situation where I am adding properties to vertices in my graph. In my case, I am adding a moduleId, which is an integer, and a kind, which is a string. I attach a weight to the edge as well. ...
2
votes
0answers
50 views

Bugs in VertexContract function?

I think there may be two bugs in the VertexContract function: 1) The updated graph does not include reasonable edgeweights 2) The function does not actually reduce the number of vertices in the ...
2
votes
1answer
168 views

Dynamic process on graph

I have a question, which I failed to find an answer to myself. I'm a casual user of Mathematica, but do have some knowledge about Dynamic module and other "Advanced" features. My problem is ...
2
votes
1answer
68 views

Finding if a graph contains an even cycle

I am looking for a simple boolean-like function which could check if a graph contains an even cycle. I'm aware there is ExtractCycles but I'm looking for a true/false output than a list of cycles.
4
votes
1answer
174 views

Intelligent vertex placement in large tree graphs

This question about graph layout is fairly general, but can be illustrated in the case of the Collatz Conjecture. Collatz created the following function over integers greater than 1: If the integer ...
3
votes
1answer
90 views

How to change the vertex shape

(Using V9 on Ubuntu) Consider the following code, to create a graph. ...