title: Scale a list of numbers from -1.0 to 1.0
body: <p>This should be an easy one.</p>
  
  <p>I have a list of numbers. How do I scale list's values, between <code>-1.0</code> and <code>1.0</code> in order for <code>min = -1</code> and <code>max = 1.0</code>?</p>