# create a random matrix that satisfies specific criteria (graph theory)

2 views (last 30 days)
Georgette Argiris on 29 Sep 2022
Commented: Matt J on 29 Sep 2022
Hello everyone, I have a 264 x 264 undirected (binary) adjacency matrix on which I calculate the nodal degree (or the number of edges connected to each node), which results in a 264 x 1 vector indicating the "degrees", or number of edges/connections, per node. Now what I would like to do is create a series of random matrices that have the same number of nodes with connections and nodal degree as the original matrix. As it will be random, it shouldn't matter what nodes those are, just that the overall nodal degree count is maintained. For instance, if I take a count of the original 264 x 1 vector, I have 79 nodes with no edges/connections, 58 nodes with 1 edge/connection, 23 nodes with 2 edges/connections, 22 nodes with 3 edges/connections, etc. So I need to generate a matrix that satisfies these criteria. I imagine that the code might be rather extensive to achieve this in MATLAB, but I would appreciate any guidance on this issue. Thank you so very much.

Matt J on 29 Sep 2022
Edited: Matt J on 29 Sep 2022
Just permute the rows and columns of the original adjacency matrix, A,
[~,is]=sort(rand(264),2);
for k=1:264
A(k,:)=A(k,is(k,:));
end
A=A(randperm(264),:);
##### 2 CommentsShowHide 1 older comment
Matt J on 29 Sep 2022
Here's another possibility,
p=randperm(264);
A2=A(p,p);
though I don't know if this spans the full space of possible solutions.

### Categories

Find more on Line Plots in Help Center and File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by