# Tagged Questions

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

263 views

### Graph does not evaluate some options when not displayed

How can I force Graph to evaluate all its options without actually displaying the graph itself? Evaluating the following code ignores the ...
283 views

### Weighted Kirchhoff Matrix?

I have a weighted graph and I want its graph Laplacian matrix (what Mathematica calls the Kirchhoff matrix in the unweighted case). Is there an easy way to get this? For example, the command: ...
143 views

### Is it possible for me to explicitly specify a point list for SpatialGraphDistribution?

The function RandomGraph[SpatialGraphDistribution[n, r]] generates a random geometric graph over $[0,1]^2$ where vertices are connected if they are within a ...
169 views

### Determining whether two k-chromatic graphs are equivalent (not simply isomorphic) using IsomorphicGraphQ?

In a previous question of mine, I asked whether Mathematica's built-in routines could determine an isomorphism for two $k$-chromatic graphs, Determining whether two $k$-chromatic graphs are isomorphic ...
428 views

### Determining whether two $k$-chromatic graphs are isomorphic (respecting vertex coloration)

Consider the case where I have two $k$-chromatic graphs $G_1$ and $G_2$, i.e. two graphs where individual vertices can be colored with one of a set of $k$ total colors, and I would like to determine ...
1k views

### How to create a planar graph from a set of random points

Question Given a set of points in the plane, how can you create a planar graph in the standard graph representation of Mathematica (version 9 or higher), from these points? Background A planar ...
132 views

### How does SocialMediaData determine vertex size

How does SocialMediaData determine the size of graph vertices, e.g. on what does the vertex size depend in, say, a Facebook friend network graph?
235 views

### HighlightGraph with style

In this picture you see a graph. The shortest path between vertex 5 and vertex 3 is highlighted in red. Instead I want blue highlighted edges of thickness 10. ...
145 views

### Tooltip not working in web deployed cdf

I deployed a CDF file in a web page. I used both Mouseover and Tooltip functions. They both work in the raw CDF file. The ...
1k views

### How do I divide the columns of a matrix by the sum of its elements?

I am trying to create a transition matrix for a network. In order to do this, I need to sum down the column (the out degree), and then divide the column by the out degree in order to normalize it. ...
285 views

### Is there something wrong with VertexConnectivity

Note: this is fixed in version 10. As I noticed in the documentation VertexConnectivity is defined as the following The vertex connectivity of a graph $g$ is ...
3k views

### How can I draw the transition diagram of a Markov chain?

I apologize for my heaviness as I am a Mathematica novice. Is there a kind soul who can tell me how to draw diagrams like those shown on page 158, 160 and 161 of this document.Chaine de Markov I ...
887 views

### Adjacency List representation of a graph

I am looking to draw a graph knowing a simple adjacency representation of the graph like: A = {{1, 3}, {2, 3}, {3, 4, 5}, {4, 5}, {5}} Where ...
2k views

### Travelling salesman with start and end points for 30 points

I am doing a route optimisation for delivery vehicles and failing dismally. Please see problem statement below. My current solution uses FindShortestTour, but this does not have defined start and end ...
109 views

### Extracting Facebook Managed accounts (pages) in Mathematica? [duplicate]

I want to use Mathematica to explore various relationships on my Facebook pages. I've been able to successfully extract information on my personal Facebook page using the build in Social Media ...
83 views

### combining NeighborhoodGraph and RandomGraph

I have Combinatorica and GraphUtilities loaded in version 9 of Mathematica. If I then set: ...
190 views

### CommunityGraphPlot doesn't size

Bug introduced in 9.0 and fixed in 9.0.1 When I need to plot a 'large' graph with CommunityGraphPlot the output is always sized at the Mathematica default value. The Graph object itself can be ...
482 views

### Export Graph to PDF

I know that I exported Graphs to PDFs before but it doesn't seem to work any more. I tried K5 = GraphData[{"Complete", 5}] Export["K5.PDF", K5] And I get a PDF ...
327 views

### The same value of VertexSize for vertices in different graphs causes different vertices size

I generated some graphs. The smallest vertices in the 1st graph should be the same size as the smallest vertices in the second graph. The smallest vertices have the same size (...
250 views

### How to get VertexDelete to work?

I'm using Mathematica 9 and want to delete a single vertex and all associated edges on a graph but can't seem to get the function VertexDelete function to work. My code is below. I declare a graph "...
613 views

### Dynamic graphics are less responsive inside a Manipulate

I have some code which displays a GraphPlot and allows the user to click on any vertex in the graph to display some information about that vertex in a popup window. ...
282 views

### Number of edges to each polygon of a graph constructed from an image

I have an image which looks like from How to convert an image to a graph and get the positions of the edges? which by using MorphologicalGraph becomes a graph ...
120 views

### Strange double evaluation using MorphologicalGraph

(MMA 9.0.0 on Mac OS/X 10.8) Please consider the following snippet (this is as SMALL as I could make it -- my attempts at making a smaller repro-case eliminated the effect that I am investigating) <...
902 views

### How to label the Vertex and, or Edge labels with their weight

I noticed that the Mathematica 9.0 documentation only mentions the usage of "Name" to label the vertexlabel or edgelabel in the Graph. Is there an option to use the Weights automatically just as "Name"...
2k views

### Finding the likeliest path in a Markov process

With Mathematica 9, we have the addition of various processes, among which the discrete Markov process. Given a transition probability matrix m, such a process is ...
186 views

### Most efficient way to output a cycle starting from an unordered list of graph vertices

I have some graph $G$ and a list of vertices $(v_1, ..., v_N) \in V$. Using graph structures in Mathematica version 9.0, what is the most efficient way to determine whether or not $(v_1, ..., v_N)$ ...
356 views

### What algorithm is Mathematica 9 using for “SpectralEmbedding” of graphs?

When I specify that a graph should be realized using the "SpectralEmbedding" procedure, what paper / algorithm for spectral embedding is this based on? I was unable to find any documentation for this....
373 views

### How can I sequentially apply different graph embeddings?

Imagine I have some graph G, and I perform a graph embedding using a command like: ...
321 views

193 views

### How do I union graph properties?

I have two graphs ...
6k views

### Solving the Travelling Salesman Problem

I've been trying to find some kind of mathematical computer software to solve the Travelling Salesman Problem. The Excel Solver is able to do it, but I've noticed there is a built-in function in ...