+<h3>Annotations and Data Sources</h3>
+<p>When you pass a URL as the data source to dygraphs, it must issue a request
+for the data before drawing the chart. This means that the chart data is not yet
+available immediately after you call <code>new Dygraph</code> and so the call to
+<code>g.setAnnotations</code> will fail. The best way around this is to use the
+<code>ready()</code> method:</p>
+
+<pre>g = new Dygraph(div, "path/to/data.csv");
+g.ready(function() {
+ // This is called when data.csv comes back and the chart draws.
+ g.setAnnotations([
+ …
+ ]);
+});
+</pre>
+