Added source Matlab code for reference

matlab/spatial/private/cluster_own.m

@@ -0,0 +1,52 @@
+function T = cluster_own(Z,nclust)
+% search down the dendogram from the root, until nclust clusters are found
+% comments added by Lu Cheng
+% 04.01.2011
+
+maxclust = nclust;
+% Start of algorithm
+m = size(Z,1)+1;
+T = zeros(m,1);
+
+% maximum number of clusters based on inconsistency
+if m <= maxclust
+  T = (1:m)';
+elseif maxclust==1
+  T = ones(m,1);
+else
+  clsnum = 1;
+  for k = (m-maxclust+1):(m-1)
+     i = Z(k,1); % left tree
+     if i <= m % original node, no leafs
+        T(i) = clsnum;
+        clsnum = clsnum + 1;
+     elseif i < (2*m-maxclust+1) % created before cutoff, search down the tree
+        T = clusternum(Z, T, i-m, clsnum);
+        clsnum = clsnum + 1;
+     end
+     i = Z(k,2); % right tree
+     if i <= m  % original node, no leafs
+        T(i) = clsnum;
+        clsnum = clsnum + 1;
+     elseif i < (2*m-maxclust+1) % created before cutoff, search down the tree
+        T = clusternum(Z, T, i-m, clsnum);
+        clsnum = clsnum + 1;
+     end
+  end
+end
+   
+function T = clusternum(X, T, k, c)
+m = size(X,1)+1;
+while(~isempty(k))
+   % Get the children of nodes at this level
+   children = X(k,1:2);
+   children = children(:);
+
+   % Assign this node number to leaf children
+   t = (children<=m);
+   T(children(t)) = c;
+   
+   % Move to next level
+   k = children(~t) - m;
+end
+