title: Convex hull area in Python?
body: <p>I have a set of points <code>A</code>. I get the convex hull <code>CH_A</code> of <code>A</code>.</p>
  
  <p>Then, I have extra points, point set <code>B</code>. I add <code>B</code> into <code>A</code> and get a bigger point set. I obtain the convex hull <code>CH_AB</code> of this bigger set containing both <code>A</code> and <code>B</code>.</p>
  
  <p>I want to quantify how much I have to pay to add <code>B</code> into set <code>A</code>. I am thinking about using an additional area to quantify this cost.</p>
  
  <p>Say <code>CH_A</code> has an area of <code>Area_A</code>, then <code>CH_AB</code> has an area of <code>Area_AB</code>. Then, I want to calculate the marginal cost as</p>
  
  <pre><code>(Area_AB - Area_A) / Area_A 
  </code></pre>
  
  <p><strong>How may I get the area of the convex hull in Python?</strong></p>