title: Trigger an event from another event in angular 5 and Material design 2
body: <p>I want to change a value of a radio button based on another radio button, but the event is never triggered and i have no console error. 
  So let's say i click on the Honda car at position 5, so the brand Civic should be selected automaticly at position 5 in the form. </p>
  
  <p>I'm using Angular 5 and Material design 2.</p>
  
  <p><strong>Here's my template:</strong></p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;mat-list&gt; 
      &lt;mat-list-item *ngFor="let id of ids"&gt;
        &lt;mat-radio-group&gt;
          &lt;mat-radio-button name="car" value="honda" id="honda{{id}}" (change)="onChangeCar(id,honda)"&gt;Honda&lt;/mat-radio-button&gt;
          &lt;mat-radio-button name="car" value="toyota" id="toyota{{id}}" (change)="onChangeCar(id,toyota)"&gt;Toyota&lt;/mat-radio-button&gt;
        &lt;/mat-radio-group&gt;
        &lt;mat-radio-group&gt;
          &lt;mat-radio-button name="brand" value="civic" id="civic{{id}}" (change)="onChangeBrand(id)"&gt;Civic&lt;/mat-radio-button&gt;
          &lt;mat-radio-button name="brand" value="camry" id="camry{{id}}" (change)="onChangeBrand(id)"&gt;Camry&lt;/mat-radio-button&gt;
        &lt;/mat-radio-group&gt;
     &lt;/mat-list-item&gt;
  &lt;/mat-list&gt;
  </code></pre>
  
  <p>In the controller i tried this, but the brand is never triggered :</p>
  
  <pre class="lang-js prettyprint-override"><code>@ViewChildren(MatRadioButton) rbuttons;
  rbuttonsList: any[];
  
  // This works
  this.rbuttons.filter(x =&gt; x.id == 'brand13')[0].checked = true;
  this.rbuttons.filter(x =&gt; x.id == 'brand131')[0].checked = true;
  
  This give me en error : Cannot read property 'rbuttons' of undefined
  // Get the ids that start with brand 13
  this.rbuttonsList = this.rbuttons.filter(x =&gt; x.id.lastIndexOf('brand13', 0) === 0);
  this.rbuttonsList.forEach(function (rbuttonIndex) {
      this.rbuttons.filter(x =&gt; x.id == rbuttonIndex.id)[0].checked = true;
    });
  </code></pre>