% ====================================================
% Machine Learning k-means Matlab example
% ====================================================

close all
clc
clear all

rng default; % For reproducibility

A = randn(100,2)*0.75+ones(100,2);
B = randn(100,2)*0.5-ones(100,2);
X = [A;B];

figure;
plot(X(:,1),X(:,2),'.');
title('Randomly Generated Data');

opts = statset('Display','final');
[idx,C] = kmeans(X,3,'Distance','cityblock',...
    'Replicates',5,'Options',opts);

figure;
plot(X(idx==1,1),X(idx==1,2),'r.','MarkerSize',12)
hold on
plot(X(idx==2,1),X(idx==2,2),'b.','MarkerSize',12)
plot(X(idx==3,1),X(idx==3,2),'k.','MarkerSize',12)
plot(C(:,1),C(:,2),'kx',...
     'MarkerSize',15,'LineWidth',3) 
legend('Cluster 1','Cluster 2','Centroids',...
       'Location','NW')
title('Cluster Assignments and Centroids')
hold off