title: insert NaNs where needed in matlab
body: <p>i have the following three vectors and i want to insert <code>NaNs</code> into <code>B</code> where <code>A</code> misses the data points in <code>An</code>. So my <code>Bn</code> should be <code>[0.1;0.2;0.3;NaN;NaN;0.6;0.7]</code>. How can i get the Bn? Thanks.--Jackie</p>
  
  <p><code>A=[1;2;3;6;7];
  An=[1;2;3;4;5;6;7];
  B=[0.1;0.2;0.3;0.6;0.7];</code></p>