function clustersize=componentsize(adj)

% COMPONENTSIZE    Calculate the sizes of the connected components of a

% network.

%

% S = COMPONENTSIZE(A) returns the sizes from largest to smallest. The

% number of components is then LENGTH(S).

%

% A must be square and if it is not symmetric COMPONENTSIZE will calculate

% the sizes of the weak components.

% Version 1.0 Ben Skellett 01/10/03

if size(adj,1)~=size(adj,2)

  error('Matrix is not square');

end

if nnz(adj-adj')~=0

   disp('Adjacency matrix is not symmetric.')

   disp('Will calculate size of weak components.')

   adj=adj+adj';

end

adj=full(adj); %in case of sparse adj

N=length(adj);

count=1; %initialize count

checked=[]; %initialize list of checked vertices to null

unchecked=1:N; %initialize unchecked vertices to all

indegreethreshold=0; %1 catches all clusters that are not single nodes, 0 catched all

while length(unchecked) > 0

  linked=unique([unchecked(1); find(adj(:,unchecked(1)))]); %find vertices connected to first vertex in 'unchecked' list

  clustersize(count)=1;

  while length(linked) > clustersize(count) %while size of cluster increases

     clustersize(count)=length(linked); %record cluster size

     [i,j]=find(adj(:,linked));

     linked=unique([i; linked]); %find vertices that link to others already in cluster

  end

  checked=unique([checked; linked]); %update checked

  unchecked=setdiff((1:N),checked); %update unchecked

  count=count+1;

end

clustersize=sort(clustersize); %sort output

clustersize=clustersize(end:-1:1);