# Tagged Questions

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

173 views

### Get histogram of number of vertices per component of graph H

I have a huge graph with ~8k vertices and ~1k components. I want a histogram showing the number of vertices for each component. How do I do this? EDIT: I'm trying ubpdqn's approach, but not gettting ...
1k views

### How to find number of connected components of graph G?

Is there a command that can count the number of components of a graph, in the same way that VertexCount[G] counts vertices?
185 views

### Importing adjacency matrix from file of 0/1 arrays

Is it possible to import adjacency matrix for graph representation, from simple text file with NxN (rows x columns) of 0s/1s: 0 1 0 0 1 0 1 1 0 1 0 0 0 1 0 0
209 views

### TreePlot, VertexRenderingFunction and stretched vertices issue

Recently I found the following TreePlot issue. For simplicity, I took an example from Mathematica Tree Drawing Tutorial and set ...
174 views

### References on functions FindGraphPartition and FindGraphCommunties

Does somebody have some interesting references on the FindGraphPartition and FindGraphCommunties[.., Method -> "Spectral"] ...
256 views

### How do I upload a graph as an adjacency list and find the betweenness centrality?

I have an undirected simple graph in a .txt file formatted as an adjacency list like this: 100 200 200 300 300 400 500 600 700 800 900 ... Every number is a node ...
215 views

### How to sort the adjecency matrix of bipartite graph so to have two off-diagonal blocks

In a bipartite graphs there are two class of nodes, say A and B. Each node of class A may interact only with nodes of the class B, and viceversa. The corresponding adjecency matrix is thus composed by ...
73 views

### How do I visualize the result of EdgeColoring[g]?

Combinatorica has a heuristic edge-coloring function EdgeColoring. When I execute it on a graph, the result is a list of integers. My guess is that an integer $i$ ...
92 views

### Why does NetworkGraphPlot`wrapper appear in my GraphPlot?

I'm making a GraphPlot of data similar to this: ...
438 views

### Different colors for nodes in tree plot

I have some list of numbers which I am plotting using TreePlot. This is the code: ...
109 views

In the documentation of Mathematica it is mentioned that you can use Hyperlink and Tooltip as wrapper in a similar manner as <...
125 views

### How do I use Subgraph to sample the $n$ vertices of a graph with the greatest connectivity?

Let $G$ be an arbitrary graph with some number of vertices $||V||$ and some number of edges $||E||$. We can use Subgraph to generate, well, a subgraph of ...
221 views

### How to efficiently distinguish the rewired edges in WattsStrogatzGraphDistribution?

The WattsStrogatzGraphDistribution function is a way to construct random graphs based on Watts and Strogatz small world model. The ...
199 views

### Plotting Network with LayeredGraphPlot with specific order

I have a network and want to plot it. I use LayeredGraphPlot, and the network is described as: ...
72 views

I would like to obtain a "slick" implementation of A*-search algorithm on Graph objects, using the built-in BreadthFirstScan (if that is possible at all). I noticed that BreadthFirstScan is static in ...
312 views

### Horizontal Tree Layout? [duplicate]

I need to display arbitrary Expressions in TreeForm, but the standard vertical layout produces too many horizontally overlapping boxes. Am I doomed to rewriting ...
66 views

### Reversibly abstracting a list of strings as a graph object where vertices represent strings and edge connect pairs of strings based on various tests

Imagine I provide you a list of arbitrary strings, say: Map[StringJoin, Tuples[{"0", "1", "2"}, 4]]. I'd like to abstract these strings as a graph object in ...
63 views

### Check Specific Connections within Graph

Say you have the skeleton of a graph: nodeset= PolyhedronData["Icosahedron", "SkeletonRules"] and you've an arbitrary list of some fraction of those nodes, say <...
285 views

### How to make a recursive code from this iterative code? (drawing tree graph)

I have a question about drawing tree graph. I use my iterative code to build a tree graph. Here it is. ...
87 views

### Get correlation matrix when using FindGraphCommunities

Does somebody know how to get the correlation matrix when using FindGraphCommunities (Social Network analysis) using the "Spectra" option? Can somebody tell me as ...
95 views

### Social Network Analysis - Get the List of InBoundEdges for Directed Graph

I wish to get the list of inwards edges for a node. IncidenceList provides both inwards and outwards list. I can of course filter with ...
239 views

### Social Network Analysis - Get the End Points of an Edge

I want to get the end points of an Edge of a Graph. For example see the following source, ...
493 views

### Don't understand why Mathematica is complaining about my Graph expression; how can I fix it?

The Tube in Arrow problem is fixed in version 10. Note that in version 10 Graph3D must be ...
114 views

So I have ...
1k views

### Fast code to generate large random graph with fixed degree sequence

I'm trying to create a function so to generate large random graph with a fixed degree sequence $\{v_1,v_2,\dots,v_N\}$, where $N$ is the number of vertices in the graph. The Mathematica function that ...
464 views

### Display a labeled multigraph

Introduced in version 9, fixed in version 10. Thanks Szabolcs for providing this screenshot showing that the bug is fixed. Despite the integration of graphs and networks, multigraphs are ...
423 views

### Finding All Chordless Simple Cycles In A Graph

I am doing a research on networks which consists of polygons with different number of sides. I am trying to find all simple cycles in a network which are chordless. As an example, consider the ...
111 views

### Extracting a single weakly connected component from a network of many weakly connected components?

Hello Mathematica friends! I've got a network with thousands of edges and vertices, but not all in one connected component. I'm trying to extract specific connected components from the network, and ...
136 views

### How to make Layer Directed Graphs (LDG) in mathematica?

I am wondering if I can make a graph like that somehow: I am new to mathematica, I tried to play with Creating a graph with variable size of vertices and variable thickness of edges . I figured if I ...
325 views

### Enumerate the 1-factors (perfect matchings) of $K_n$

Introduction I would like to enumerate the 1-factors, or (near-)perfect matchings, of the complete graph Kn. The adjacency list representation for Kn is basically { (x, y) | 1 ≤ x < y ≤ n }. For ...
516 views

### Nested list to graph

The following nested list can be regarded as a representation of a (tree) graph: ...
94 views

### How can I change VertexWeights in a Graph?

Bug introduced in 9.0 or earlier and fixed in version 10.0.0 I evaluate ...
2k views

I am the admin of a Facebook group for our year at university and wanted to graph the members of the group like you can with your own friends so we can find the isolated people and get rid of them (as ...
202 views

### Saving a graph of a great number of nodes

I'm developing a code where I get graphs with over 10K nodes. These graphs have a particular relationship between clustering and degree that I need to save for future analysis. The problem is when I ...
206 views

### Improving performance in the generation of random (directed acyclic) graphs

I need to generate large (directed, acyclic, transitive) graphs. My code in Mathematica gets very slow for large numbers of vertices. I've tried a number of approaches and I can't find any significant ...
154 views

### Using Graph to cull correlated lists

I have a set of lists that represent molecular descriptors. I need to identify which descriptors are highly correlated and eliminate the correlated pairs. I can represent the connectivity by ...
547 views

### A* algorithm for finding shortest path in a graph

FindShortestPath finds the shortest path between two vertices in an edge-weighted graph, allowing a choice between the Dijkstra and Bellman-Ford algorithms. In my (limited) understanding, both of ...
475 views

### Flow/graph-based programming in Mathematica?

Is it possible in Mathematica to write a program inside a graph? For example if you have a bunch of different If[] statements that you need to embed within one ...
232 views

### Writing results directly to file

I am trying to find all simple paths in a large directed graph (542 vertex, density ~ 5%) between two nodes. For this purpose, I use the algorithm from this thread. Unfortunately, my computer is ...
286 views

### Generating a (random) 2-dimensional cellular network

I want to generate a network of random cells like the following picture: The general idea is to generate some random points (x,y) as coordinate of a vertex and then randomly choose some of these ...
110 views

### Checking connectedness of a graph

I am trying to use the Combinatorica package in a Mathematica version 8 in the following code: ...
444 views

### Visualize a tree structure using TreeGraph

I have a code that generates a tree of graphics objects. The structure can be visualized like this, with each Rule constituting a parent child relationship: ...
106 views

### Connecting a vertex to middle of an edge with GraphPlot?

using GraphPlot I'd like to make directed arrow connecting a vertex (node) to the middle of an edge but couldn't find a way. Is this even possible using GraphPlot or other graphics-related commands in ...
223 views

### How to impose control over vertex-to-vertex Graph edges?

I’m working on a Markov Chain and hope there is a way to impose control over how Mathematica places edges to connect vertices in a Graph. My Markov Chain currently consists of 4 vertices with 2 of the ...
134 views

### Signed Graph from positive and negative correlations

I want to create a signed graph where the edges of my graph are either green (for a positive correlation) or red (for a negative correlation). I only managed to create a graph from a tresholded ...
240 views

### Why is my PageRank result in Mathematica converging this way?

I am using this technique to find the PR of these 3 pages. It converges to something it shouldn't be. I tried the same iteration in Java and 2 pages come up with 1.333 and the other one as 0.666. ...
381 views

### Pairwise distances of points and classification using GraphDistanceMatrix

The challenge Given $n$ points in $\mathbf{R}^3$ and a cutoff distance, $d$, I would like to determine all pairs of points that are separated by less than the given cutoff distance, $d$, and all ...
191 views

### GridGraph layout with added edges

I noticed that the nice symmetric layout of a grid graph gets distorted when additional edges are added to the graph. Is there way to prevent that from happening and to keep the rectangular, grid-like ...