title: KNN classification with categorical data
body: <p>I'm busy working on a project involving k-nearest neighbour regression. I have mixed numerical and categorical fields. The categorical values are ordinal (e.g. bank name, account type). Numerical types are, for e.g. salary and age. There are also some binary types (e.g., male, female).</p>
  
  <p>How do I go about incorporating categorical values into the KNN analysis?</p>
  
  <p>As far as I'm aware, one cannot simply map each categorical field to number keys (e.g. bank 1 = 1; bank 2 = 2, etc.), so I need a better approach for using the categorical fields. I have heard that one can use binary numbers - is this a feasible method? 
  Advice would be much appreciated.</p>