How do I retrieve groupwise leaf nodes with Hierarchical Clustering?

Question

I am using Hierarchical Clustering wants to know how to retrieve the leaf nodes for each cluster groups.   To give you the idea, please refer to the illustration just above the "Dendrograms."     I would like to find:       Group 6: 4, 5     Group 7: 1, 3     Group 8: 1, 3, 4, 5     (The enclosing group necessarily includes all: 1, 2, 3, 4, 5)

John Michell · Accepted Answer

As of MATLAB R2015a, a function for retrieving groupwise leaf nodes with Hierarchical Clustering is not available.
 
As a workaround consider the following script:
 

  rng default;  % For reproducibility
 
    X = [1   2; ...
 
         2.5 4.5; ...
 
         2   2; ...
 
         4   1.5;...
 
         4   2.5];
 
    Y = pdist(X);
 
    Z = linkage(Y);
 
    dendrogram(Z);
 
    % A
 
    n = size(Z,1)+1;
 
    v = eye(n,n*2-1)>0;
 
    for i = 1:n-1 
 
        v(:,i+n) = any(v(:,Z(i,[1 2])),2); 
 
    end
 
    v = v(:,n+1:end)
 
    % B
 
    [index_row , index_column] = ind2sub(size(v), find(v));
 
    index_row(index_column == 1).'
 
    index_row(index_column == 2).'
 
    index_row(index_column == 3).'

How do I retrieve groupwise leaf nodes with Hierarchical Clustering?

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