title: how do I find all documents with a field that is NaN in MongoDB?
body: <p>I want to delete all geospacial fields that are NaN so I can properly index my MongoDB.</p>
  
  <p>How do I find all documents that have this though?</p>
  
  <pre><code>db.collection.find( { field: {$not: { $type: 1 } } })
  </code></pre>
  
  <p>won't work since NaN is of type Number.</p>