collectiveMerging.m

function [ clusterIndex ] = collectiveMerging( Zmatrix, para )
%COLLECTIVEMERGING extract components from Z matrix
% Mar.28,2013, Bolei Zhou
linkGraph = Zmatrix > para.threshold;
[ clusterIndex ] = linkGraph2cluster( linkGraph );

end

function [ clusterIndex ] = linkGraph2cluster( linkGraph )
[row,col] = find(linkGraph==1);
pairData = [row';col'];
clusterIndex = pairClustering(pairData,size(linkGraph,1));
end


function clusterIndex = pairClustering(pairwiseData,totalNum)

clusterNum = 0;
clusterIndex = zeros(1,totalNum);

for i = 1:size(pairwiseData,2)
    curPair = pairwiseData(:,i);
    curPairAlabel = clusterIndex(1,curPair(1));
    curPairBlabel = clusterIndex(1,curPair(2));
    
    if curPairAlabel == 0 && curPairBlabel == 0
        clusterNum = clusterNum+1;
        curPairLabel = clusterNum;
        clusterIndex(1,curPair(1)) = curPairLabel;
        clusterIndex(1,curPair(2)) = curPairLabel;
    elseif curPairAlabel~=0 && curPairBlabel==0
        clusterIndex(1,curPair(2)) = curPairAlabel;
    elseif curPairBlabel~=0 && curPairAlabel==0
        clusterIndex(1,curPair(1)) = curPairBlabel;
    else
        combineLabel = min(curPairAlabel,curPairBlabel);
        clusterIndex(1,find(clusterIndex==curPairAlabel)) = combineLabel;
        clusterIndex(1,find(clusterIndex==curPairBlabel)) = combineLabel;
    end
    

end
newClusterNum = 0;
for i = 1:max(clusterNum)
    curClusterIndex = find(clusterIndex==i);
    if length(curClusterIndex)<10
        clusterIndex(curClusterIndex) = 0;   
    else
        newClusterNum = newClusterNum+1;
        clusterIndex(curClusterIndex) = newClusterNum;
    end
end
    
end