title: change selected item in md-select programmatically
body: <p>I want to initially (on page load) set the current schoolclass item in the md-select.</p>
  
  <p>This code sets the selected schoolclass but it is not reflected in the <code>md-select</code> visually.</p>
  
  <pre><code>$scope.selectedSchoolclass = schoolclasses.length &gt; 0 ? schoolclasses[0] : null;
  
  &lt;md-input-container&gt;
      &lt;label&gt;Schoolclasses&lt;/label&gt;
      &lt;md-select ng-model="selectedSchoolclass"  md-on-close="getPupils()"&gt;
          &lt;md-option ng-repeat="s in schoolclasses" ng-value="{{s}}"&gt;
              {{s.schoolclassNumber}}
          &lt;/md-option&gt;
      &lt;/md-select&gt;
  &lt;/md-input-container&gt;
  </code></pre>
  
  <p>When I use <code>md-selected="$first"</code> then it is selected visually in the <code>md-select</code> but I get an error from a computed property which seem to evaluate first just before the $first. Thus I cannot set the first schoolclass as the selected schoolclass from html. I have to do it via JS in the controller.</p>
  
  <p>How can I do that?</p>