title: Distance between point and a line (from two points)
body: <p>I'm using Python+Numpy (can maybe also use Scipy) and have three 2D points </p>
  
  <pre><code>(P1, P2, P3); 
  </code></pre>
  
  <p>I am trying to get the distance from P3 perpendicular to a line drawn between P1 and P2. Let <code>P1=(x1,y1)</code>, <code>P2=(x2,y2)</code> and <code>P3=(x3,y3)</code></p>
  
  <p>In vector notation this would be pretty easy, but I'm fairly new to python/numpy and can't get anythng that works (or even close).</p>
  
  <p>Any tips appreciated, thanks!</p>