% 
% Written by:
% -- 
% John L. Weatherwax                2005-08-14
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

close all; drawnow; 
clc; 
clear; addpath( '../../Code/eda_data' ); addpath( '../../Code/eda_toolbox' ); addpath( '../Chapter1' ); 

X = load_sparrow(0,0,0,0);
[n,p] = size(X);

y = pdist(X,'euclidean'); 

if( 0 ) 
  z = linkage(y,'single'); 
  figure; dendrogram(z); 
  title( 'sparrow dendrogram with single linkage' ); 
  saveas( gcf, '../../WriteUp/Graphics/Chapter5/prob_5_2_sparrow_sl', 'epsc' ); 
end

z = linkage(y,'average'); 
figure; dendrogram(z); 
title( 'sparrow dendrogram with average linkage' ); 
saveas( gcf, '../../WriteUp/Graphics/Chapter5/prob_5_2_sparrow_av', 'epsc' ); 

% Implemente the inconsistency metric ... not sure that this is correct ... 
%
if( 0 ) 
  y_ic = inconsistent(z);
  % take the last column ... it constains the inconsistency coefficient: 
  ic = y_ic(:,end); 
  figure; plot( ic, 'o' ); 
  
  % from this plot we look like 0.6 should be a good threshold ... 
  t = 0.6; 
  tmp = cluster(z,'cutoff',t); 
end

% Consider the uniform-gap statistics
% -- modified from Example 5.7
% 
K = 5; 
B = 50; 
link_method = 'complete'; 
%link_method = 'average'; % <- gives only one cluster ... 
pdist_method = 'euclidean'; 
[Z, khat, gap, Wobs, muWb] = gap_uniform(X,K,B,link_method,pdist_method); 
fprintf('khat = %10d\n',khat); 

figure; plot(1:K,Wobs,'o-',1:K,muWb,'x-')
legend({'Observed';'Expected'})
xlabel('Number of Clusters k')
ylabel('Observed and Expected log(W_k)')

figure,plot(1:K,gap,'o-'),title('Gap')
xlabel('Number of Clusters k')
ylabel('Gap')
saveas( gcf, '../../WriteUp/Graphics/Chapter5/prob_5_2_sparrow_gap', 'epsc' ); 

% using the suggested khat clusters lets visualize them: 
%
khat = 3; % even thought we predict two clusters ... lets plot three to observe the hypothetical outliers
cinds = cluster(Z,'maxclust',khat); 
plot_labeled(X(:,1),X(:,2),cinds); 
saveas( gcf, '../../WriteUp/Graphics/Chapter5/prob_5_2_sparrow_clusters', 'epsc' );