# Tagged Questions

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

395 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–...
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 ...
102 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 ...
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 ...
411 views

### Hasse Diagrams in Mathematica using an arbitrary relation

As a kludge to draw Hasse diagrams for an assignment, I wrote(based on this): ...
356 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. ...
84 views

### Mathematically Eliminated in Baseball [closed]

Earlier today the Yankees were mathematically eliminated from the playoffs. Determining when this condition is satisfied for any given team is complicated but can be solved as a maximum flow problem, ...
107 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 - ...
184 views

### getting vertices in order from spanning tree

I've got spanning tree for some weighted graph (edges labeled 1-6) - for example: ...
358 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 ...
268 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 ...
175 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)? ...
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. ...
190 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 ...
85 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 ...
208 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", ...
310 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 ...
955 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 ...
232 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 ...
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 ...
623 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 ...
135 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 ...
154 views

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 ...
281 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-...
479 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?
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 ...
972 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' ...
163 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 ...
232 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 ...
393 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 ...
910 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 "...
434 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 ...
320 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 ...
282 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 ...
69 views

### Importing additional custom data in DIMACS format

I have graphs in DIMACS format, with vertex colors specified. The vertex colors are denoted by lines n u c, where u is the ...
696 views

### How can one draw a network with nodes and links in a grid shape?

I'd like to be able to use MMa's graphics to make something like this which I know must absolutely be possible (and probably easy) with MMa. I don't actually even need different colors (though that'...
123 views

### Using FindGraphCommunities, write community membership for each vertex to CSV

I have a network that I've loaded into Mathematica, and I've used FindGraphCommunitites[network,Method->"Hierarchical"] to identify the communities in the ...
141 views

### Expected graph distance in random graph

I am trying to use the functionality of Expectation and Probability for random graphs, in particular for percolation models. ...
623 views

### Positioning Vertices in a Graph

I made a graph that has a given number at each vertex: I want to place vertex 1 above vertex 2 if value of vertex 1 is larger than of vertex 2. And also, vertices with same value should be located ...
161 views

### Fix the size of vertices and arrow in graphs

I defined an option to draw nicely the graph. But I have a problem with the different size obtained. For example, the layout of the first graph is what I want to have for all other graphs I will ...
78 views

### What Algorithm Does Mathematica use to Calculate Betweenness Centrality for Unweighted Graphs?

I recently asked this question on the Mathematics SE. Does anyone know, as a follow up, what algorithm Mathematica uses to calculate the betweenness centrality vector (of $N$ elements) for an ...
486 views

### How to get all leaves from a graph's specific node

Let's say I have this graph (The code to generate the graph is at the end) How can I extract all the leaves comming from, let's say "cluster3"?, i.e. {100, 92, 87, 89} I guess I have to first ...
99 views

### Graph plotting: specify layers for layered drawing

Mathematica can do layered graph drawing with LayeredGraphPlot or GraphLayout -> "LayeredEmbedding". Is it possible to ...
564 views

### Mathematica 10 Graph issue

Bug introduced in 10.0.0 and fixed in 10.0.2 Please try to evaluate this code in Mathematica 10. ...
198 views

### Undirected Network and its Monte Carlo Simulation

So I have this array of points, in the form {x, {y,z}}, where x is the node number assigned when I used the locator pane to make a network, and y and z are its unitary coordinates. The graph is made ...
157 views

### Agglomerate output to Graph

I'm using the HierarchicalClustering package to cluster some data. So let's say I have this: ...
213 views

### Systemic bugs in GraphPlot and related functions such as TreePlot and TreeForm

Bug introduced in 7.0.1 or earlier and fixed in 10.3.0 I believe I have come across a rather curious bug in TreeForm: ...
251 views

### Cellular Automata Neighborhood as Node connections

Can I use the CellularAutomation[] function where the neighborhood is defined by the connections between nodes? For example, if 1 -> 2, 1 -> 3, 1 -> 8, 1 ->1, then the neighborhood of node 1 is the ...