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

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1
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1answer
170 views

Can degenerating Nicomachus' triangle down to $0$ area by using `Graph` be done?

I noticed a pattern in Nicomachus' Triangle that might be used to reduce the triangle to the number line. If the Edge size could be set to the absolute difference ...
2
votes
2answers
163 views

Speeding up the generation of all k-edge-coloring of a graph

A $k$-edge-coloring of a graph $G=(V,E)$ is a function from $E$ to $\{1,\ldots,k\}$, so in other words every edge of $G$ receives one of the $k$ colors available. (In particular, note that we are not ...
12
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2answers
241 views

Graph smoothing keeping vertices fixed?

Context Given a Graph like this one: ...
2
votes
0answers
78 views

Spread multiple edges by a specified scaled distance (Mathematica 10)

Is there way to spread multiple edges by a specified scaled distance for Graph function in Mathematica 10, something similar to MultiedgeStyle in GraphPlot for example, I would like to write: ...
1
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0answers
130 views

Using NMinimize to solve the Multi Commodity Flow problem

I have the following optimization problem and I was hoping to solve it with NMinimize. Unfortunately, I don't get the desired result. I would like to get an optimal vector for $d_{e}$. This is how ...
1
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0answers
154 views

Replace part in a matrix that matches specific pattern

I have the following problem. Given a matrix L which looks as follows, Matrix L is a link, route matrix. Further, I got the following vector (d), which indicates the demand per vertex combination. ...
11
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2answers
245 views

Finding the minimum vertex cut of a graph

Bug introduced in 9.0.1 or earlier and fixed in 10.2.0 Note: FindVertexCut is new in 9.0. It seems that Mathematica is not correctly finding the smallest set of ...
9
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0answers
97 views

Graph: PropertyValue changes and Dynamic

I almost never work with Graph in Mathematica but lately I helped someone with it. For this, I tried to make an animation using ...
8
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1answer
234 views

Vertex merging in graph?

Given a Graph such as the one produced with the following code ...
0
votes
1answer
58 views

Verticepair - route matrix

I have the following problem. I have two lists: list1 defines all possible commodities in a network g. E.g. Form vertex 1 to ...
4
votes
2answers
124 views

Equivalent of RadialOutside for Graph VertexLabels

I'm creating a circular graph and want the labels to be placed on the outside of the vertices in a circular manner on the outside of the graph. I've been playing around with the ...
14
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2answers
582 views

How to build a 3D graph from a 3D matrix?

Following this and that question and the corresponding answers, Mathematica can build 2D graph from 2D matrices. Question How to make the corresponding 3D graphs from 3D cubes? Attempt ...
0
votes
2answers
74 views

Getting FerrersDiagram to work

I am trying to generate FerrersDiagram (see http://reference.wolfram.com/language/Combinatorica/ref/FerrersDiagram.html), any clues to getting it to work? I get error message for the following: ...
6
votes
1answer
373 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. ...
1
vote
1answer
48 views

Unexpected behaviour with GraphIntersection and GraphDifference

I run into some unexpected behaviour of GraphIntersection and GraphDifference. Behaviour is the same for both so the example is only on the GraphIntersection: Suppose I have two lists of directed ...
9
votes
2answers
254 views

Self-loops in Graph may not display correctly or export correctly to PDF (due to BezierCurve problem)

Bug introduced in 10.0 and persisting through 10.3 Problem is due to a BezierCurve bug. I don't understand why the following does not work: ...
4
votes
1answer
184 views

Vertex Labelling and Word wrap

I am having trouble formatting vertex labels, explicitly adding line breaks to Vertex labels for word wrapping and other purposes. I have explored the pane option suggested here but when I include ...
2
votes
1answer
396 views

Dynamic graph construction and visualization (Watts' “Small Worlds” α-model)

I need some help in creating a Mathematica program for building and visualizing Watts' "Small Worlds" α-model. This is a variant of the more known (and much more simple) β-model (also known as Watts–...
8
votes
5answers
437 views

Is there a neat way to generate the odd set constraints matrix?

Given a undirected graph $G=(V,E)$, I am trying to generate a related matrix $M$, where columns are indexed by $E(G)$ and rows are indexed by all odd subsets of $V(G)$. I can finish this task using ...
1
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2answers
104 views

Add weighted edge to a graph in Mathematica 8

Is it possible to add an edge with a specific weight to a Mathematica Graph object? The function EdgeAdd has no option for the weights, nor the ...
1
vote
1answer
53 views

Graph objects for LineGraph

When I enter for example G = Part[GraphData[10],1]; LG = LineGraph[G]; I get error message that LineGraph requires a graph ...
5
votes
2answers
417 views

Hasse Diagrams in Mathematica using an arbitrary relation

As a kludge to draw Hasse diagrams for an assignment, I wrote(based on this): ...
6
votes
3answers
360 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. ...
3
votes
1answer
108 views

how to depict a network with a legend

Because my network nodes have real world names more than a few characters long, I'd like to label them with a shortcut, e.g., n1, n2, n3, ..., and put a legend on the side something like this: n1 - ...
2
votes
2answers
186 views

getting vertices in order from spanning tree

I've got spanning tree for some weighted graph (edges labeled 1-6) - for example: ...
2
votes
1answer
367 views

Finding Hamiltonian path in Graph

I have weighted, undirected full graph (generated from points in R^2), where weight between every two vertices are euclidean distance between corresponding pair of points. What I'm trying to do is ...
7
votes
1answer
278 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 ...
2
votes
1answer
176 views

Planar graph layout

Mathematica supplies planar graph layout, which draws a nice picture of a planar graph, but is there any way to get one's hands on the layout? For example, to find its faces (complementary regions)? ...
5
votes
3answers
107 views

GraphIntersection Problem

I Have a problem when plotting 2 functions. I want to find out where the two graphs intersect eachother. That said, I want the coordinates (x, y) of the point. ...
2
votes
1answer
195 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
86 views

Mathematica 8: EdgeList and CommunityStructureAssignment shadowing problem

I'm facing some issues when trying to use the CommunityStructureAssignment function from the GraphUtilities package in Mathematica 8. I'd like to output a ...
5
votes
2answers
209 views

Graph expansion on Mathematica

Is there a way by which Mathematica can be given a graph as an input and be asked to find its expansion? Note: By "expansion" I mean the quantity called "isoperimetric number" or "Cheeger constant", ...
9
votes
4answers
311 views

Multiple Forms of Transportation Between Cities

I want to be able to show different connections between cities based on modes of transportation. For instance, you could walk to any city, but it would take a long time, you could take a train, but ...
14
votes
6answers
966 views

Finding all paths of certain length between vertices in path graph, non-simple ones too

First I will tell you what my ultimate goal is, because maybe there's another way of doing it other than what I am trying. I need a list of all $(a_1, a_2, \ldots, a_N)$ tuples that satisfy certain ...
2
votes
1answer
235 views

Creating an Adjacency Matrix to connect an undirected network

I used the locator pane to map a network, specifically the Maryland Power Grid. What I would like is to have some sort of numbering of the vertices on the unconnected network, how to make an adjacency ...
0
votes
0answers
42 views

Graph embedding and edge weights [duplicate]

Does functions like GraphPlot take in to account edge weights in case of springelectrical embedding? In case of spring electrical embedding I expect the vertices connected by heavy edges to be pulled ...
14
votes
3answers
644 views

Binary decision diagrams (BDD)

I would like to use Mathematica to help me simplify a given Binary Decision Diagram (i.e. pick the optimal variable ordering). I don't seem to find anything at all on the topic, although it is ...
6
votes
2answers
136 views

How to use DegreeGraphDistribution with directed graphs?

DegreeGraphDistribution supports directed graphs because it has a DirectedEdges option. How can I specify the in-degree ...
4
votes
1answer
155 views

Undocumented overload for Graph?

I stumbled (here, in the expression for the block diagram) upon a version of Graph that I don't see in the documentation over here. That documentation admits three overloads (the following are in my ...
5
votes
0answers
284 views

How to draw block diagrams as Graph objects?

In the documentation ClosedLoopResponsesWithAPIDController, There is a very nice block diagram. I want to create my own block diagrams similar to this. I clicked on the diagram and pressed "command-...
8
votes
1answer
489 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?
18
votes
3answers
1k views

How can I construct and visualize a hypergraph?

A hypergraph is a generalization of a graph, in which an edge can connect more than two vertices. Thus you can think of an edge in an hypergraph as a subset of nodes. Since version 8, Mathematica has ...
5
votes
3answers
986 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' ...
7
votes
1answer
165 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 ...
0
votes
1answer
236 views

Turning sound into a graph

I'm writing a comprehensive text on graphs and Mathematica and in this context I have this, let's call it, creative gap between sound and graphs. There are plenty of ways one can create graphs from ...
3
votes
1answer
402 views

How to convert a sparse array to a graph?

s = Import["hello.mat"]; t = GraphEmbedding[Graph[s[[1]]], "GridEmbedding"]; I get the following error: GraphEmbedding::graph: A graph object is expected ...
4
votes
5answers
931 views

Ordering the Boundary points of a Polygon

I feel like this should be simple, but I keep running into walls. Say someone gives you the coordinates of the vertices of a pentagon and the center point of the hexagon. Is there any way to get an "...
3
votes
2answers
436 views

How to create a 'shortest-path link matrix'?

I am currently struggling with a problem in Mathematica. I have a randomly generated weighted Barabasi-Albert graph and a corresponding demand matrix of the same size. I'm generating the graph with ...
6
votes
1answer
321 views

Citation of the algorithms used in FindGraphCommunities

For my research work I need to put a comparison of different community detection algorithms. Instead of implementing all those algorithms once again, I would like to use the methods already provided ...
4
votes
2answers
283 views

Coordinate extraction and manipulating graphs as graphics objects

Consider the image below: GraphData[{"Wheel", 7}] Is it possible in Mathematica to lay several of these Graph along each ...