[yt-dev] Issue #1246: Mjup/cm**3 can't be used as a unit for density (yt_analysis/yt)

[Matthew Turk]

New issue 1246: Mjup/cm**3 can't be used as a unit for density
https://bitbucket.org/yt_analysis/yt/issues/1246/mjup-cm-3-cant-be-used-as-a-unit-for

Matthew Turk:

This script:

```
import yt
ds = yt.load("data/IsolatedGalaxy/galaxy0030/galaxy0030")
p = ds.r[0.5,:,:].plot("density")
p.set_unit("density", "Mjup/cm**3")
```

(`.plot()` only works in the notebook evidently)

results in this traceback:

```
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
/home/mturk/yt-conda/lib/python2.7/site-packages/IPython/core/formatters.pyc in __call__(self, obj)
    309             method = get_real_method(obj, self.print_method)
    310             if method is not None:
--> 311                 return method()
    312             return None
    313         else:

/home/mturk/yt/yt/yt/visualization/plot_container.pyc in newfunc(*args, **kwargs)
     76             # it is the responsibility of _setup_plots to
     77             # call args[0].run_callbacks()
---> 78             args[0]._setup_plots()
     79         rv = f(*args, **kwargs)
     80         return rv

/home/mturk/yt/yt/yt/visualization/plot_window.pyc in _setup_plots(self)
    896             parser = MathTextParser('Agg')
    897             try:
--> 898                 parser.parse(colorbar_label)
    899             except ParseFatalException as err:
    900                 raise YTCannotParseUnitDisplayName(f, colorbar_label, str(err))

/home/mturk/yt-conda/lib/python2.7/site-packages/matplotlib/mathtext.pyc in parse(self, s, dpi, prop)
   3124             self.__class__._parser = Parser()
   3125 
-> 3126         box = self._parser.parse(s, font_output, fontsize, dpi)
   3127         font_output.set_canvas_size(box.width, box.height, box.depth)
   3128         result = font_output.get_results(box)

/home/mturk/yt-conda/lib/python2.7/site-packages/matplotlib/mathtext.pyc in parse(self, s, fonts_object, fontsize, dpi)
   2372                         err.line,
   2373                         " " * (err.column - 1) + "^",
-> 2374                         six.text_type(err)]))
   2375         self._state_stack = None
   2376         self._em_width_cache = {}

ValueError: 
\ \ \left(\frac{M_{\rm{Jup}}{\rm{cm}^{3}}\right)
                                         ^
Unknown symbol: \right (at char 41), (line:1, col:42)
```

`Mearth/cm**3` works.