Get node names after a graph condensation

I have an adjacency matrix adj and a cellarray nodeManes that contains names that will be given to the graph G that will be constructed from adj

So I use

G = digraph(adj,nodeNames);

And I get the following graph :

Now , I want to find the strongly connected components in G and do a graph condensation so I use the following :

C = condensation(G);
p2 = plot(C);

So I get the following graph :

So I have 6 strongly connected components , but my problem is that I lost the node names , I want to get something like :

Is that any way to get the nodes names in the result of the condentation ?

Thanks.

Answer 1

[Christine Tobler]

Here is some code that does this:

 bins = conncomp(G);
 compNames = cell(max(bins), 1);
 for ii=1:length(bins)
     if isempty(compNames{bins(ii)})
         compNames{bins(ii)} = G.Nodes.Name{ii};
     else
         compNames{bins(ii)} = [compNames{bins(ii)} ', ' G.Nodes.Name{ii}];
     end
 end
 C.Nodes.Name = compNames;
 plot(C);

There's no one-line command to combine several node names based on the vector of bins used in condensation, so I wrote a for-loop to do this instead.

[stam dadi]

Thank's

[Waseem AL Aqqad]

Thanks, Christine

Answer 2

[Walter Roberson]

Stealing basic technique from Christine, and reworking it without a loop:

bins = conncomp(G);
temp = accumarray(bins.', (1:length(bins)).', [], @(IDX) {G.Nodes.Name(IDX)});
C.Nodes.Name = cellfun(@(CS) strjoin(CS, ', '), temp, 'uniform', 0);

[Christine Tobler]

Very nice!

[stam dadi]

Thank's

[Walter Roberson]

I wouldn't have known the calls to make without Christine's post.

[stam dadi]

Solved..

[stam dadi]

Walter Robinson ....How can I plot the resulted graph C of type struct ? I used the plot fonction but got :

Not enough input arguments

[Steven Lord]

It shouldn't be a struct. In your original code it was the output of a call to condensation, which would return a digraph if called with a digraph. Walter and Christine's codes modified that digraph, specifically the names of the digraph's nodes.

[stam dadi]

I get it as a struct . The problem is it was working and I got the plot , after that I start getting the error !

[Walter Roberson]

You would get a struct as an output if you had assigned the output

C = condensation(G);

to some other variable name than C

[stam dadi]

yes.. I just checked , I accidently deleted the line :

C = condensation(G);

Thank's

[Waseem AL Aqqad]

Wow! Thanks.