title: Angular show NaN value into inputs
body: <p>I figure out that by default Angular with the <code>ng-model</code> directive doesn't show the <code>NaN</code> value into an input:</p>
  
  <pre><code>&lt;input type="number" class="form-control" id="calcmouldSugNOfCavitiesCost" disabled
       step=0.01
       ng-model="$parent.mouldTAB.sugNOfCavitiesCost"&gt;
  </code></pre>
  
  <p>so if <code>$parent.mouldTAB.sugNOfCavitiesCost</code> is equal to <code>NaN</code> the input is empty.</p>
  
  <p>Instead of this behaviour i would like to show <code>NaN</code>.  </p>
  
  <p>it's possible ?  </p>