title: Output of IDX in Kmeans?
body: <p>I have a 1000x6 dataset and using the below kmeans script is fine but when I want to output one of the clusters it only comes out as one column?</p>
  
  <pre><code>%% cluster
  opts = statset('MaxIter', 100, 'Display', 'iter');
  [clustIDX, clusters, interClustSum, Dist] = kmeans(data, K, 'options',opts, ...
  'distance','sqEuclidean', 'EmptyAction','singleton', 'replicates',6);
  
  %% plot data+clusters
  figure, hold on
  scatter3(data(:,1),data(:,2),data(:,3), 5, clustIDX, 'filled')
  scatter3(clusters(:,1),clusters(:,2),clusters(:,3), 100, (1:K)', 'filled')
  hold off, xlabel('x'), ylabel('y'), zlabel('z')
  
  %% plot clusters quality
  figure
  [silh,h] = silhouette(data, clustIDX);
  avrgScore = mean(silh);
  
  %% Assign data to clusters
  % calculate distance (squared) of all instances to each cluster centroid
  D = zeros(numObservarations, K);     % init distances
  for k=1:K
  %d = sum((x-y).^2).^0.5
  D(:,k) = sum( ((data - repmat(clusters(k,:),numObservarations,1)).^2), 2);
  end
  
  % find  for all instances the cluster closet to it
  [minDists, clusterIndices] = min(D, [], 2);
  
  % compare it with what you expect it to be
  sum(clusterIndices == clustIDX)
  
  % Output cluster data to K datasets
  K1 = data(clustIDX==1)
  K2 = data(clustIDX==2)... etc
  </code></pre>
  
  <p>Shouldnt <code>K1 = data(clustIDX==1)</code> output the full row information? Not just one column but six like the original dataset?  Or is this just outputting the distances?</p>