title: LaTeX annotation in MATLAB
body: <p>I am trying to add a LaTeX annotation to a figure in MATLAB, but I'm running in to some problems. If I run</p>
  
  <pre><code>figure
  annotation('textarrow', [0.3, 0.6], [0.3, 0.6], 'String', '$$\tau_{\mathrm{abc}}$$', 'interp', 'latex')
  </code></pre>
  
  <p>I would expect an arrow with the correct annotation. That is indeed what I get, but I also receive the following warning messages:</p>
  
  <pre><code>Warning: Unable to interpret TeX string "$$\tau_{\mathrm{abc}}$$" 
  &gt; In scribe.textarrow.createTextArrow&gt;localChangePosition at 409
    In scribe.textarrow.schema&gt;localSetToText at 357
    In scribe.textarrow.createTextArrow at 152
    In scribe.textarrow.textarrow at 11
    In annotation at 149 
  Warning: incomplete command in TeX text string:
  '$$\tau_{\mathrm{abc}}$$' 
  &gt; In scribe.textarrow.createTextArrow&gt;localChangePosition at 409
    In scribe.textarrow.schema&gt;localSetToText at 357
    In scribe.textarrow.createTextArrow at 152
    In scribe.textarrow.textarrow at 11
    In annotation at 149 
  </code></pre>
  
  <p>So, my question is, why do I get these warnings, and how do I correct the underlying problem?</p>