Tagged Questions

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

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 ...
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 ...
241 views

Graph smoothing keeping vertices fixed?

Context Given a Graph like this one: ...
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: ...
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 ...
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. ...
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 ...
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 ...
234 views

Vertex merging in graph?

Given a Graph such as the one produced with the following code ...
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 ...
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 ...
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 ...
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: ...
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. ...
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 ...
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: ...
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 ...
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–...
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 ...
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 ...
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 ...
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): ...
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. ...
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 - ...
186 views

getting vertices in order from spanning tree

I've got spanning tree for some weighted graph (edges labeled 1-6) - for example: ...
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 ...
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 ...
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)? ...
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. ...
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 ...
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 ...
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", ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
155 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 ...
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-...
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?
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 ...
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' ...
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 ...
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 ...
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 ...
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 "...
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 ...