Code and Results for Chapter 8

• run_all.py (runs and demonstrates all commands from the text)
  
• chap_8_ex_1.py (optimizes the number of neighbors to use with k nearest neighbors)
  
• chap_8_ex_2.py (implements leave-one-out cross-validation and tests)
  
• chap_8_ex_3.py (feature selection using genetic optimization)