title: Matplotlib Error: LaTeX was not able to process the following string: 'lp'
body: <p>This is the error I'm getting from the function I'll provide at the bottom:</p>
  
  <pre><code>'latex' is not recognized as an internal or external command,
  operable program or batch file.
  Exception in Tkinter callback
  Traceback (most recent call last):
    File "C:\python27\lib\lib-tk\Tkinter.py", line 1486, in __call__
      return self.func(*args)
    File "C:\python27\lib\site-packages\matplotlib\backends\backend_tkagg.py", lin
  e 278, in resize
      self.show()
    File "C:\python27\lib\site-packages\matplotlib\backends\backend_tkagg.py", lin
  e 349, in draw
      FigureCanvasAgg.draw(self)
    File "C:\python27\lib\site-packages\matplotlib\backends\backend_agg.py", line
  469, in draw
      self.figure.draw(self.renderer)
    File "C:\python27\lib\site-packages\matplotlib\artist.py", line 59, in draw_wr
  apper
      draw(artist, renderer, *args, **kwargs)
    File "C:\python27\lib\site-packages\matplotlib\figure.py", line 1079, in draw
      func(*args)
    File "C:\python27\lib\site-packages\matplotlib\artist.py", line 59, in draw_wr
  apper
      draw(artist, renderer, *args, **kwargs)
    File "C:\python27\lib\site-packages\matplotlib\axes\_base.py", line 2092, in d
  raw
      a.draw(renderer)
    File "C:\python27\lib\site-packages\matplotlib\artist.py", line 59, in draw_wr
  apper
      draw(artist, renderer, *args, **kwargs)
    File "C:\python27\lib\site-packages\matplotlib\axis.py", line 1116, in draw
      renderer)
    File "C:\python27\lib\site-packages\matplotlib\axis.py", line 1065, in _get_ti
  ck_bboxes
      extent = tick.label1.get_window_extent(renderer)
    File "C:\python27\lib\site-packages\matplotlib\text.py", line 741, in get_wind
  ow_extent
      bbox, info, descent = self._get_layout(self._renderer)
    File "C:\python27\lib\site-packages\matplotlib\text.py", line 311, in _get_lay
  out
      ismath=False)
    File "C:\python27\lib\site-packages\matplotlib\backends\backend_agg.py", line
  223, in get_text_width_height_descent
      renderer=self)
    File "C:\python27\lib\site-packages\matplotlib\texmanager.py", line 670, in ge
  t_text_width_height_descent
      dvifile = self.make_dvi(tex, fontsize)
    File "C:\python27\lib\site-packages\matplotlib\texmanager.py", line 417, in ma
  ke_dvi
      report))
  RuntimeError: LaTeX was not able to process the following string:
  'lp'
  Here is the full report generated by LaTeX:
  </code></pre>
  
  <p>This is the function I'm using that creates the above error:</p>
  
  <pre><code>def Derivative( inputArrayList,rowNumber_from_top ):
      for image in inputArrayList:
          rowValues = image[0][rowNumber_from_top]
          for i in range(len(rowValues)):         
              # Perform the difference derivative estimation
              if i == 0 or i == (len(rowValues) - 1):
                  rowValues[ i ] = 0 # set edges to 0
              else:
                  derivative = (rowValues[ i+1 ] - rowValues[ i-1 ])/(2.0)
                  rowValues[ i ] = derivative
          plt.rc('text', usetex=True)
          plt.rc('font', family='serif')
          plt.plot(rowValues,color="k")
          plt.ylim( (0,image.max() + 10.0) )
          plt.title(r"$\displaystyle\sum_{n=1}^\infty\frac{-e^{i\pi}}{2^n}$")
          plt.show()
  </code></pre>
  
  <p>Notice the line <code>plt.title(r"$\displaystyle\sum_{n=1}^\infty\frac{-e^{i\pi}}{2^n}$")</code>. I've taken this from the <a href="http://matplotlib.org/users/usetex.html#text-rendering-with-latex" rel="noreferrer">first graph</a> on Matplotlib's site (and I've tried running that program as well that they provide) and I cannot seem to get it to work. I'm almost certain it's a simple fix (like maybe I'm missing a LaTeX module or something?).</p>
  
  <p>The whole goal was to be able to use the command <code>\displaystyle</code> in the title and labels of the plot to make fractions larger.</p>
  
  <p>I apologize if this is a duplicate (although I can't find a similar issue), I just need a pointer to get me going in the right direction.</p>
  
  <p>Thank you for your time,</p>
  
  <p>Brandon</p>