Tagged Questions

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

54 views

How to check if (u,v) and (v,u) edges are in a given directed graph

I have a graph and i want a module to run through all the edges of this graph and check whether (u,v) edge is in this graph and (v,u) edge is in another given graph.
29 views

Weighted graph vizualization [duplicate]

Is it possible to visualize a weighted graph, so lines on screen would reflect weight? I.e., be longer, or shorter depending on edge weight? Slight OT: which graph visualising libraries/tools can do ...
81 views

Coloring network edges by weight using GraphPlot

Following up on a previous question about how to color the nodes (vertices) of a network (graph) according to a color scaling of a property of those nodes, I'm now asking basically the same thing ...
92 views

IsomorphicGraphQ fails to recognize that two empty graphs are identical

Bug introduced in 9.0.1 or earlier and persisting through 10.2.0 Consider the following two graphs: ...
34 views

How to perform operations with vertices from any edge on a Graph object

I'm trying to get the vertices from an large list of edges on a Graph object in Mathematica 10. I need to operate them, adding, substracting dividing. As an ...
37 views

Why does (Layered)GraphPlot lose labels and renumber vertices?

I define a graph of numbers as vertices, but also labeled, like g=Graph[{Labeled[1 \[DirectedEdge] 5, "text1"]…},VertexLabels -> {79 -> "text2",…}]. This is ...
45 views

Count graphs with fixed number of vertices incluing isomorphisms

I'm trying to use the listgraph function in the Combinatorica package: Needs["Combinatorica"] g = ListGraphs[5]; ShowGraph /@ g However, it only returns all the ...
156 views

Efficient solution for a discrete assignment problem with pairwise costs

Let's consider a simple graph with N vertices, and a corresponding set of N items. The goal of the problem is to assign every item to a vertex on the graph so that sum of a per-edge (that is ...
52 views

Network Graph: show highly connected components

I want to create a network graph without the small subgraphs which are disconnected from the big network graph. Suppose I want to visualize the edgelist: ...
141 views

Arbitrary shape GridGraph

There is a function GridGraph that generates a finite square lattice graph. Is there a way to make a generalized solution (e.g. with hexagons, or triangles instead of squares)? To put it in more ...
46 views

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Graph, overlapping vertexlabels

The graph I create is based on more then 1000 different word-combinations. A example looks like this: text = {{word, word1}, {word1, word2}, {word1, word3}, {word,word4}, {word,word5}, ...
38 views

Can I rely on the ordering of the adjacency matrix? [closed]

Suppose I have created a Graph[{1,2..n}, {1->3, etc}], and I take the adjacency matrix of that graph. Can I rely on the fact that the i-th entry in the graph is the i-th node in the matrix? Or maybe ...
229 views

Why don't the arrowheads show for this directed graph?

It's very weird, but the first graph is shown as undirected (dots connected by lines, not arrows. The second is shown as directed, with arrows. I'm using the cloud version of Mathematica. ...
35 views

How can I get the vertex labels of an existing graph?

For example, if there is a graph g = CompleteGraph[5, VertexLabels -> {1 -> "v1", 2 -> "v2", 3 -> "v3", 4 -> "v4", 5 -> "v5"}] How can I later ...
49 views

Compute complete graph and make minimum spanning tree

I'd like to plot a complete Graph and then compute the Minimum spanning tree of it. I already can make a complete graph out of a list that countrydata gives me: ...
78 views

Iterative Tree Plot for the Sum of an Integer's Digits Squared

I am trying to make a graph that depicts integers<100 mapping to the sum of their digits squared. I can do this for one iteration, but I don't know how to do it for more than one, or until the new ...
58 views

Graph: vary color/length vertextlabels based on frequency

In this example I use a small network of 5 words. ...
68 views

What is the correct way to assign and use properties of vertices in graphs?

I'm using Mathematica 10, but I'm having a hard time getting it to do anything useful for network analysis because I'm having a hard time working with node properties and analyzing the graph by its ...
94 views

Slow-down encountered for RandomChoice in large lists

I was wondering if anyone could help me to speed up this code snippet which creates simple (sparse) networks by preferential attachment. The algorithm adds a vertex and an edge each time interval. ...
61 views

Functionality of FindMaximumFlow

I know that the superseeded function NetworkFlow (needs Combinatorica) uses Goldberg-Tarjan's Push-Relabel-Algorithm but i cant find any information on Mathematica's built-in-function (...
42 views

reset the value of a variable [closed]

Folks, I have a problem in populating a matrix without overriding the values. After performing computations for various values for j, I want to store these values in following matrix. Here is the ...
60 views

Shortest Common Superstring for all k-length strings on an alphabet

Given all strings of length $k$ of an alphabet of size $n$. This gives $n^{k}$ strings. Now I want to create one superstring that contains all these strings as substrings. They hopefully strongly ...
88 views

Finding nonequivalent 3-cycles and edges of a given graph

So I have three graphs defined by the following nested list, I'm using this list notation instead <-> notation because it is more convenient for another part ...
2k views

Trying to Visualize a Collatz - The Collatz conjecture

So I'm new in this and learning--- and I happen to have this collatz collatz[x_, y_] := If[x == 3*y || x == 2*y + 1 || y == 3*x || y == 2*x + 2, 2, 0] So i want ...
58 views

Why does TreePlot ignore the vertex labels in a TreeGraph argument?

Example (watch the vertex labels): aTree = TreeGraph[{"a" -> "b", "a" -> "c"}, VertexLabels -> "Name"] ...
97 views

Graph generation from a non-paired edge list

The elements in e = {{6414, 6598, 6927}, {7, 1035, 2382, 6927}, …} are the graph nodes; for example, {6414,6598,6927} is ...
72 views

Powerset Animation/Invisible Vertices/Graph Layout

I wanted to visualize the cumulative powerset construction process and came up with two functions: ...
296 views

Creating a hyperlink graph from Wikipedia

This goes out to all the Mathematica experts - I'm hoping to get some helpful comments, ideas or code for that matter. In my attempts to maximize learning efficiency I had the idea to create an ...
37 views

Unexpected behaviors with Edge Weights

Noticed some bizarre behavior when subgraphing on weighted graphs, which probably extends to graphs with arbitrary edge properties. I construct a weighted graph with five edges, defining a specific ...
228 views

Possible improvements to this Syracuse (3x+1)/2 graph?

This algorithm produces the Syracuse disjoint tree graph without any duplicates. No need for Union, For, and ...
152 views

Efficiently find all connected subgraphs

Is there a way to generate all the connected subgraphs of a graph in mathematica without going through all the subsets of the nodes and checking if the subgraph is connected (which will be ...
59 views

Avoiding overlap in rendering of GraphPlot

I'm trying to visualize some 'graphs' (i.e. the mathematical objects with nodes and edges) using GraphPlot[]. I am defining the nodes using objects such as ...
51 views

VertexDelete not working on graph with VertexWeight

Bug introduced in 10.0 and persisting through 10.2.0 Good afternoon, I have observed an "unexpected behaviour" with VertexDelete and a graph with vertex weights. This is a minimal working example: ...
78 views

Graph: Coloring Edges individually

CODE: Graph[{Style[0 -> 1, Red], Style[0 -> 1, {Blue, Dashed}]}] This mathematica code will make both lines solid Red, since they belong to the same two ...
58 views

RandomGraph with specific constraints

I need to generate random connected simple graphs (no loops) with the constraint that exactly two vertices must only have a single edge. I can create many connected graphs (but very few will have the ...
117 views

How does Mathematica calculate its AdjacencyMatrix[ ] and VertexDegree[ ]

I define a graph: ...
40 views

Create graph K5, delete 2 edges and 2 vertex, create adjacency matrix [duplicate]

I need help about this problem. I should create graph K5, delete 2 edges and 2 vertex from it and from the new graph create adjacency matrix. I have poor knowledge and i don't need anyone to solve the ...
81 views

DeleteVertex in Kpartite graph

How can i make K7,2 graph and how can i delete 2 vertex? Btw, i need to use package -> Combinatorica`; I tried this: ...
65 views

Graph not drawing after VertexDelete

I'm very new to Mathematica and am currently trying the VertexDelete function, but after using it, my graph isn't drawing. Input: ...
201 views

Enforce graph symmetry

I am using ...
87 views

Bug introduced in 10.0 and persisting through 10.2.0. Note: TransitiveReductionGraph is new in 10.0. In Mathematica 10.0 and 10.1, according to the ...
76 views

How to use the edge routing of LayeredDigraphEmbedding when specifying explicit vertex coordinates?

The "LayeredDigraphEmbedding" GraphLayout uses an edge routing algorithm which produces nice and readable diagrams and curved ...
53 views

FindShortestPath does not work

The FindShortestPath doesn't work in this graph, can someone tel me what's wrong? ...
126 views

How do I get the adjacency Matrix from a random graph [closed]

I am using the command g = RandomGraph[{8, 13}]; GraphPlot[g, VertexLabeling -> True] to plot a random graph with n nodes and l edges. Once the program has ...
63 views

Efficient Implementation of Resistance Distance for graphs?

Is there an implementation of the resistance distance matrix (or just resistance matrix) for graphs available in Mathematica?
125 views

Can I make a simple game in Mathematica?

Here is the game outline: $\hspace{2.5cm}$ There is one player. The player ($\mathscr{L}$) moves from node to node limited by the directed arrows. As the player moves, $\mathscr{G}_{\Huge\cdot}$ ...
147 views

How to rotate a complete graph without image rescaling while rotating

How do I rotate the following image? ...