title: Removing points in a vector based on another
body: <p>I've two vectors with data x and y. Let's say the first one is the distance and the second the temperature.</p>
  
  <p>How can I remove from both x and y all points which distance is lower a constant distance 'd' between two consecutive points ( xi - xi-1 )</p>
  
  <pre><code>x = (1,2,3,8,12)
  y = (10,12,11,9,12)
  </code></pre>
  
  <p>remove points with a distance smaller than 5</p>
  
  <pre><code>x  = 1, 2(out as 2-1 &lt;5), 3 (out as 3-1 &lt;5), 8, 12 (fine as last even thoug 12-8&lt;5)
  x  = (1,8,12)
  y  = (10,9,12)
  </code></pre>