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

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4
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0answers
51 views

Why NearestNeighborGraph gives different result for numerical List and exact List

In mathematica 10.3 there is a function called NearestNeighborGraph. I found some behavior of it that I don't understand. First I generate a 2D list like this <...
3
votes
0answers
143 views

Neural network playground

I came across this Neural Net Playground demonstration based on Google's Tensorflow package. It visualizes the data processing inside a neural network and allows you to tweak parameters and ...
7
votes
1answer
133 views

Vertexes possibility estimate in graph

I have graph which represents runner race events. Vertex means runner, edge means running event between runners, edge weight is how much more seconds runner won running race against opponent. (running ...
7
votes
1answer
151 views

How to convert a graph to a mesh region

As we know,the region is very convenient in Mathematica.And we can convert a MeshRegion into graph like this ...
0
votes
1answer
51 views

How to change the bipartite into a normal form

If we have a bipartite,we can change its form into a normal form like this g1 = GraphData[{8, 579}] ...
1
vote
0answers
40 views

Is this a bug between RelationGraph and BipartiteGraphQ?

Inspired by yode's latest question I was playing around with RelationGraph and found that BipartiteQ seems to be unable to ...
4
votes
2answers
125 views

A unexpected behavior in RelationGraph

Bug persisting through 10.4.1 Firstly we get these idiom ...
2
votes
1answer
51 views

None connected graphs for n=59? [closed]

For some reason GraphData["Connected", 59] gives no graphs, is this a bug?
3
votes
1answer
47 views

Use (network) graph as vertex

I have a Markov chain with graphs as the states. Basically how one network structure would evolve to another in the next period. To avoid confusion, I'll use the term "network" instead of "graph". I ...
3
votes
2answers
163 views

Question about this Sieve of Eratosthenes graph

I googled for images of graphs and found nothing that even comes close to this one, so I want to experiment some more. ...
0
votes
0answers
63 views

Enumerating all orientations of an undirected graph

Given an undirected graph $G$, an orientation of $G$ is a directed graph obtained by assigning every edge a direction, a superorientation of $G$ is a directed graph obtained by orienting every edge in ...
2
votes
2answers
116 views

How to extract the structure of relationships amongst variables in a system of equations? [closed]

Mathematica being a CAS, I would have thought what I'm trying to do a natural task. But I have not been able to find any information on this in the Internet. Basically, I have a large collection of ...
4
votes
2answers
163 views

How to get the Perfect Matching or Near-Perfect Matching

I have found the Perfect Matching's definition in Wiki. A perfect matching (a.k.a. 1-factor) is a matching which matches all vertices of the graph. That is, every vertex of the graph is incident ...
0
votes
0answers
27 views

Different edge Weights for edge Graph

I have a weighted Grid Graph with Diagonal Edges (nXm). I want to add different cost to the parallel edges. All Horizontal(0°-->) will have edgeweight of 1.8 All Horizontal(180°<--) will have ...
3
votes
2answers
200 views

How to make a disconnected graph to be 1-edge-connected(but not 2-edge-connected) with some shortest edge

Assume I have a graph.You can run following code to get it. Import["http://goo.gl/NaH6rM"]["http://i.stack.imgur.com/EyAKW.png"] It is a disconnected graph.But ...
1
vote
1answer
63 views

DirectedEdges -> False not working

Consider this graph, that I downloaded from the OpenConnectome project. Graph[EdgeList[cElegans], DirectedEdges -> False] // DirectedGraphQ outputs: ...
10
votes
4answers
259 views

Tom's family how to cross the bridge

A interesting question.Tom's family just have a flashlight which will extinguish after 30 seconds.They wanna go through a bridge to arrive opposite side with the flashlight.But as the picture,they ...
21
votes
1answer
1k views

How to divide the wine into two equal portions

There is a 8-liter bottle is full of wine. There are two empty bottles that have capacity 5-liters and 3-liters. How can these three bottles be used to separate the wine into two 4-liter portions? ...
2
votes
1answer
106 views

How to find the shortest path going through some specified vertices

I have a grid graph g = GridGraph[{12, 12}, VertexLabels -> "Name"] We can find a shortest from 1 to 144 ...
0
votes
1answer
67 views

How do I display a graph theory problem? [closed]

If I have several nodes and the distances that they have between one another, how do get Mathematica to display this as a graph? And also maybe define this graph in such a way that I can then use ...
3
votes
0answers
32 views

WeightedAdjacencyMatrix does not complete for Connected Graph

Please see code snippet below - I have a weighted, connected graph that models a software process using a DiscreteMarkovProcess. I set some of the edge weights to ...
1
vote
0answers
61 views

How-to make large graph more readable?

One day, I found myself curious about different topics in mathematics. So, I stumbled uppon a website (considerably old website) where author has tabularized mathematics into subjects and associated ...
4
votes
4answers
129 views

GridGraph with diagonal edges

I have n x n GridGraph (or n x m), I trying to add diagonal edges for each square box automatically and then assign same weights to the diagonals, same weights to horizontal edges and same weights to ...
2
votes
1answer
70 views

Some strange graph from “RelationshipGraph”

I want use this code to graph the all of function in image-processing. ...
3
votes
3answers
84 views

Reverse the layout when using “DiscreteSpiralEmbedding”

I have a graph such as NestGraph[# + 1 &, 1, 10, GraphLayout -> "DiscreteSpiralEmbedding", VertexShapeFunction -> "Name", VertexSize -> .2] But ...
4
votes
1answer
27 views

How to get the VertexWeight list or EdgeCapacity list in a graph

The graph of Mathematica.We have VertexList or EdgeList.So we can get it convenient like ...
6
votes
1answer
101 views

Is a bug about the FindFundamentalCycles?

My graph is ...
3
votes
1answer
72 views

How to make the graph to specific layout

For the artistic,the graph layout could be more important sometimes.So I must to put a bad sentence to describe the clumsy GraphLayout of ...
4
votes
1answer
80 views

Odd behaviors of FindKPlex

Bug introduced in 9.0 and persisting through 10.4 FindKPlex is new in 9.0. I have a example about it. ...
0
votes
2answers
84 views

How to make a graph form imported spreadsheet data [closed]

I've three csv files: v.csv for vertex data, like this: 1 2 3 ... e.csv for edges: 1,2 2,4 2,24 3,1 ... and vcoor.csv for vertex coordinates: 23.4, 35.2 23.4, 40.3 ... I know how to construct a ...
0
votes
1answer
64 views

How can I code a graph visibility criterion using an If-statement?

The visibility criterion can be defined as follows: two arbitrary data values $(ta , ya)$ and $(tb , yb)$ are visible to each other if any other data $(tc, yc)$ placed between them fulfills the ...
2
votes
1answer
41 views

Certainty of the New Vertex Name after using EdgeContract

It appears that when I use EdgeContract on an undirected graph, the vertex that is the result of contracting an edge is always named the smaller of the two vertices....
3
votes
1answer
18 views

Why does Mathematica report the VertexEccentricity of a disconnected vertex as zero?

"For a disconnected graph, all vertices are defined to have infinite eccentricity" So, why does Mathematica report the VertexEccentricity of a disconnected vertex as 0 instead of ...
1
vote
1answer
26 views

VertexContract, VertexReplace and non-anonymous collapsed node

Can the standard VertexContract or VertexReplace functions display a name for the collapsed node ? Here is a minimal example: <...
2
votes
1answer
55 views

Trying to remove duplicate isomorphic graphs in a list of graphs [duplicate]

I am working on a Mathematica program that involves taking a graph and generating all of its single-edge contractions. When I get this list of contractions, it often happens that many of the graphs ...
3
votes
1answer
65 views

How can I get the arguments of the function Graph?

If I have f0 = f[x,y,z] and I am interested in the list of the arguments, what I do is ...
9
votes
1answer
150 views

Petrie polygon projection of a hypercube graph

I am trying to generate the Petrie polygon projection of the 8-cube in Mathematica, like this one: I tried using, for example, the HypercubeGraph function: ...
0
votes
0answers
15 views

Acyclic Directed Graph, NeighborhoodGraph and ancestors [duplicate]

What is the correct way of find the list of a given vertex' ancestors in an ADG ? I am thinking that a pattern in NeighborhoodGraph might be the solution or a negative option for the degree of ...
3
votes
1answer
67 views

Find independent vertex sets

I'm trying to find all independent vertex sets for a given graph. Note that they may not be maximal independent sets. There is a function in Mathematica called ...
8
votes
2answers
238 views

Plot a 3-cycle graph with clockwise-directed edges

When I try to plot a 3-cycle, the edge direction is always counter-clockwise. The plotting code is ...
6
votes
2answers
119 views

Small World network on a square grid

My aim is to generate a 2D Small World network on a square grid. i.e. 20x20. With a probability of 5%, one node rewires from an adjacent node to a random node of the grid, allowing some long distance ...
2
votes
0answers
120 views

How to make a flowchart? [closed]

I'd like to make a flow chart in similar to this: I think it's more of a layout and stylistic question for a graph - how to style a graph with labeled edges and vertices so that it looks like a ...
1
vote
1answer
49 views

Trying to get simple excel data to be imported as a social network directed graph

My data has two columns that we'll call A and B. The columns proceed as such A B A1 B1 A2 B2 A3 B3 .... I'm trying to make this into a directed graph where A1 has an outgoing edge to B1 and ...
3
votes
1answer
112 views

Deleting vertices from Graph and preserving Structure?

My goal is to remove vertices from graphs (and the edges from them) and then take GraphComplement to find out cut sets in graphs with sink and source such as here. So How can I delete vertices from a ...
3
votes
3answers
106 views

Random bipartite graphs?

RandomGraph[{n,m}] generates a random graph with $n$ vertices and $m$ edges. I want to generate a random bipartite graph, like ...
2
votes
2answers
106 views

VertexDelete Problem

I am doing a straightforward deletion of a set of vertices in a Tree using Mathematica. ...
4
votes
2answers
123 views

How can I make this code to count Hamiltonian paths faster?

I have this very basic code to count Hamiltonian paths in a graph: ...
10
votes
1answer
91 views

Arrows from GraphicsComplex not converted to Normal form correctly

Bug introduced in 7.0 or earlier and persisting through 10.4.0 Show @ Graph[{1 -> 2, 2 -> 3}, Frame -> True] Normal @ % Is this a pure bug, or have ...
5
votes
0answers
54 views

What's meaning of `VertexConnectivity`?

Are there a conflict in this two place in documentation? In the Basic Examples: Then the Properties & Relations But actually:
0
votes
0answers
66 views

Plotting a graph on a torus and another surfaces [duplicate]

I'm trying to figure out how to plot a graph on a surface. My goal is to represent a planar embedding of $ K_5$ in a torus. I have encountered this post, where you can find an explanation how to plot ...