title: MATLAB GUI callbacks and function variable scope
body: <p>I think I have a basic understanding of scope, but I am a bit confused as to how this would work in a MATLAB GUI.  </p>
  
  <p>For instance, if I had a GUI that did a surf plot on an axes based on input from editBox1, I would have:</p>
  
  <p>An updateAxes function that would update the axes with input from editBox1 (str2double(get(handles.editBox1, 'String'))).</p>
  
  <p>An editBox1 callback that would call the updateAxes function.</p>
  
  <p>Does it violate the idea of scope for updateAxes to directly use the get function? Should I be passing in the content of editBox1 as a parameter to updateAxes?</p>