LINQ Except query with an XElement
<p>I have a data set that I receive from a service. The data comes in XML format. We are given an XElement object with all the data. The structure of the XML document is very simple. Looks like this:</p>

<pre><code>&lt;root&gt; 
 &lt;dataPoint&gt;
   &lt;id&gt;1&lt;/id&gt;
   &lt;param1&gt;somedata&lt;/param1&gt;
   &lt;param2&gt;somedata&lt;/param2&gt;
 &lt;/dataPoint&gt;
 &lt;dataPoint&gt;
   &lt;id&gt;2&lt;/id&gt;
   &lt;param1&gt;somedata&lt;/param1&gt;
   &lt;param2&gt;somedata&lt;/param2&gt;
 &lt;/dataPoint&gt;
&lt;/root&gt;
</code></pre>

<p>Of course, I have a large number of dataPoints. I also have a list (List) with the id's of dataPoints being displayed in a GUI. What I'd like to have is the dataPoints that ARE NOT displayed on the GUI so I can manipulate only those and not the whole data set.
Thanks</p>
