Extract subgraph using names

Hi MathWorks community,

I have a graph G which has 6119 nodes. I want to extract a subgraph H with only 539 nodes. The name of the nodes that need to be extract are in a seperate 539 x 1 double called NodeID. I tried the following code, but received 'Error using graph/subgraph (line 29) Nodes must be a vector of unique node indices, a vector of unique node names, or a logical vector of length equal to the number of nodes.'.

H = subgraph(G,strtrim(num2str(NodeID)))

I am not sure what the problem is and what should I do to resolve the problem.

For your reference, I am also attaching my G.Nodes and NodeID as a mat. file.

Thanks!

[Matt J]

It would be easier to troubleshoot if you attached the actual inputs G and NodeID (in a .mat file) as opposed to a picture of them.

[IrisL]

Thanks. Just edit my post.

Answer 1

[Steven Lord]

I'd use a string array, both when naming the nodes initially and when extracting the subgraph.

B = bucky;
n = height(B);
G = graph(B, string(1:n))

G = 
  graph with properties:

    Edges: [90×2 table]
    Nodes: [60×1 table]

nodeIDs = randperm(n, n/4) % Extract 1/4 of the nodes

nodeIDs = 1×15

5 25 43 55 4 13 7 44 54 14 33 22 17 35 59

G2 = subgraph(G, string(nodeIDs))

G2 = 
  graph with properties:

    Edges: [5×2 table]
    Nodes: [15×1 table]

figure
plot(G)
title('Bucky')

figure
plot(G2)
title('Bucky/4')