er)</h3>
<p>Sets the filter function for this data layer.</p>
<table>
<thead>
<tr>
<th>Options</th>
<th>Value</th>
<th>Description</th>
</tr>
</thead>
<tbody><tr>
<td>filter (<em>required</em>)</td>
<td>function</td>
<td>a function that takes GeoJSON features and returns true to show and false to hide features.</td>
</tr>
</tbody></table>
<p><em>Example</em>:</p>
<pre><code>var featureLayer = L.mapbox.featureLayer(geojson)
    // hide all markers
    .setFilter(function() { return false; })
    .addTo(map);