title: Elasticsearch script_fields with geo_shape
body: <p>I would like to use elasticsearch to annotate data with geographic belonging.</p>
  <p>I'm quite new to elasticsearch so I'm a bit unsure about the correct word to search for. I might have missed an obvious answer, but I didn't find what I was looking for in the Elasticsearch documentation.</p>
  <h3>Problem description :</h3>
  <p>I have a huge set of events stored in a ElasticSearch database. I would like to query these events, and for each event, add a kind of scripted field telling is the event point is within a given polygon.</p>
  <p>I should be able to do this with two queries :</p>
  <ul>
  <li>a first one retrieving a batch of events</li>
  <li>another one filtering the same events with a geo_shape filter
  I could then check for every event in the first list if it's also in the second one.</li>
  </ul>
  <p>But it would be so much easier to have one query, with the event document annotated with an <code>is_within_polygon</code> boolean.
  And it would also allow me to check against multiple polygons in one query.</p>
  <p>Is it possible with Elasticsearch ?</p>