title: MATLAB: Simple function that takes in a matrix as an argument
body: <p>I have the following simple function that returns the (1,1) element in MATLAB:</p>
  
  <pre><code>function out = blah(A)
      out = A(1,1);
  end
  %% test
  A = [1 2; 3 4];
  
  out = blah(A);
  </code></pre>
  
  <p>However, the output I get is:</p>
  
  <pre><code>Undefined function 'blah' for input arguments of type 'double'.
  </code></pre>
  
  <p>What gives?</p>