Here is a quick and dirty calculation of connexed component using adjacent matrix. It returns the same output as MATLAB conncomp function in BINS and BINSIZES.
% TMW example
s = [1 2 2 3 3 3 4 5 5 5 8 8 9];
t = [2 3 4 1 4 5 5 3 6 7 9 10 10];
G = digraph(s,t,[],20);
A = G.adjacency;
A = spones(A + A'); % no need to symmetrize for undirected graph
n = size(A,1);
bins = zeros(n,1);
k = 0;
while any(bins==0)
x = sparse(find(~bins,1), 1, true, n, 1, n);
y = x;
while true
y = A*y;
y = y > 0 & ~x;
if nnz(y) == 0
break
end
x = x | y;
end
k = k+1;
bins(x) = k;
end
% Formating output
nodes = (1:n)';
Comptable = table(nodes, bins);
CompSet = accumarray(bins, nodes, [], @(x) {sort(x)'});
binsizes = accumarray(bins, 1);
Display
plot(G,'Layout','layered')
k = length(CompSet);
fprintf('Graph has %d bins(s)\n', k);
Comptable
binsizes
for i=1:k
fprintf('Compnent %d: Nodes = %s\n', i, mat2str(CompSet{i}));
end
