title: How to check if geo point lies close to a set of other geo points
body: <p>I have a list of geo-points and radiuses around them</p>
  
  <pre><code>P1 = { lat1, lon1, rad1 }
  P2 = { lat2, lon2, rad2 }
  ...
  </code></pre>
  
  <p>I can reorder this list and change representation in any way before hand.</p>
  
  <p>My tasks is: given another point</p>
  
  <pre><code>Q = { latQ, lonQ }`
  </code></pre>
  
  <p>I need to find if <code>Q</code> lies close enough to at least one of <code>P</code>s, i.e. distance </p>
  
  <pre><code>d(Q, P[i]) &lt; P[i].rad
  </code></pre>
  
  <p>I can just iterate over each point, calculate distance and compare it with <code>.rad</code>,  but there must be a more efficient way.</p>