ValueError: zero-size array to reduction operation maximum
I have recently incountered a strange issue which only happens on the dev branch.  I've mostly encountered it when trying to display the dataframe, such as with print or wanting ipython output.  Displaying a column/series of the dataframe works fine, just not displaying the whole frame.  The dataframe is originally constructed with from_json(orient='values') from a json string retrieved from MongoDB.  The index is then reset after the initial json load.

The reason I installed the dev branch was that I needed to switch to the latest in order to find a workaround to a slicing/selection issue regarding the latest dateutils version.

In anycase I ended up going back to 0.12.0 because I kept getting caught up on this.  At first it looks like an error with IPython but it also complains in a regular python script if I try to print the dataframe.

Here is the traceback.

```
In [8]: e.spectrum.df
Out[8]: ---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-8-0462e2de8255> in <module>()
----> 1 e.spectrum.df

/usr/lib/python2.7/site-packages/IPython/core/displayhook.py in __call__(self, result)
    245             self.start_displayhook()
    246             self.write_output_prompt()
--> 247             format_dict, md_dict = self.compute_format_data(result)
    248             self.write_format_data(format_dict, md_dict)
    249             self.update_user_ns(result)

/usr/lib/python2.7/site-packages/IPython/core/displayhook.py in compute_format_data(self, result)
    155 
    156         """
--> 157         return self.shell.display_formatter.format(result)
    158 
    159     def write_format_data(self, format_dict, md_dict=None):

/usr/lib/python2.7/site-packages/IPython/core/formatters.py in format(self, obj, include, exclude)
    150             md = None
    151             try:
--> 152                 data = formatter(obj)
    153             except:
    154                 # FIXME: log the exception

/usr/lib/python2.7/site-packages/IPython/core/formatters.py in __call__(self, obj)
    479                 type_pprinters=self.type_printers,
    480                 deferred_pprinters=self.deferred_printers)
--> 481             printer.pretty(obj)
    482             printer.flush()
    483             return stream.getvalue()

/usr/lib/python2.7/site-packages/IPython/lib/pretty.py in pretty(self, obj)
    360                             if callable(meth):
    361                                 return meth(obj, self, cycle)
--> 362             return _default_pprint(obj, self, cycle)
    363         finally:
    364             self.end_group()

/usr/lib/python2.7/site-packages/IPython/lib/pretty.py in _default_pprint(obj, p, cycle)
    480     if getattr(klass, '__repr__', None) not in _baseclass_reprs:
    481         # A user-provided repr.
--> 482         p.text(repr(obj))
    483         return
    484     p.begin_group(1, '<')

/usr/lib/python2.7/site-packages/pandas-0.12.0_1168_gb1485a3-py2.7-linux-x86_64.egg/pandas/core/base.pyc in __repr__(self)
     53         Yields Bytestring in Py2, Unicode String in py3.
     54         """
---> 55         return str(self)
     56 
     57 

/usr/lib/python2.7/site-packages/pandas-0.12.0_1168_gb1485a3-py2.7-linux-x86_64.egg/pandas/core/base.pyc in __str__(self)
     33         if compat.PY3:
     34             return self.__unicode__()
---> 35         return self.__bytes__()
     36 
     37     def __bytes__(self):

/usr/lib/python2.7/site-packages/pandas-0.12.0_1168_gb1485a3-py2.7-linux-x86_64.egg/pandas/core/base.pyc in __bytes__(self)
     45 
     46         encoding = get_option("display.encoding")
---> 47         return self.__unicode__().encode(encoding, 'replace')
     48 
     49     def __repr__(self):

/usr/lib/python2.7/site-packages/pandas-0.12.0_1168_gb1485a3-py2.7-linux-x86_64.egg/pandas/core/frame.pyc in __unicode__(self)
    455             width = None
    456         self.to_string(buf=buf, max_rows=max_rows, max_cols=max_cols,
--> 457                        line_width=width, show_dimensions=True)
    458 
    459         return buf.getvalue()

/usr/lib/python2.7/site-packages/pandas-0.12.0_1168_gb1485a3-py2.7-linux-x86_64.egg/pandas/core/frame.pyc in to_string(self, buf, columns, col_space, colSpace, header, index, na_rep, formatters, float_format, sparsify, nanRep, index_names, justify, force_unicode, line_width, max_rows, max_cols, show_dimensions)
   1286                                            max_rows=max_rows, max_cols=max_cols,
   1287                                            show_dimensions=show_dimensions)
-> 1288         formatter.to_string()
   1289 
   1290         if buf is None:

/usr/lib/python2.7/site-packages/pandas-0.12.0_1168_gb1485a3-py2.7-linux-x86_64.egg/pandas/core/format.pyc in to_string(self, force_unicode)
    373             text = info_line
    374         else:
--> 375             strcols = self._to_str_columns()
    376             if self.line_width is None:
    377                 text = adjoin(1, *strcols)

/usr/lib/python2.7/site-packages/pandas-0.12.0_1168_gb1485a3-py2.7-linux-x86_64.egg/pandas/core/format.pyc in _to_str_columns(self)
    332                                    minimum=max_colwidth, truncated=truncate_v)
    333 
--> 334                 max_len = max(np.max([_strlen(x) for x in fmt_values]),
    335                               max_colwidth)
    336                 if self.justify == 'left':

/usr/lib/python2.7/site-packages/numpy/core/fromnumeric.pyc in amax(a, axis, out, keepdims)
   2123         except AttributeError:
   2124             return _methods._amax(a, axis=axis,
-> 2125                                 out=out, keepdims=keepdims)
   2126         # NOTE: Dropping the keepdims parameter
   2127         return amax(axis=axis, out=out)

/usr/lib/python2.7/site-packages/numpy/core/_methods.pyc in _amax(a, axis, out, keepdims)
     15 def _amax(a, axis=None, out=None, keepdims=False):
     16     return um.maximum.reduce(a, axis=axis,
---> 17                             out=out, keepdims=keepdims)
     18 
     19 def _amin(a, axis=None, out=None, keepdims=False):

ValueError: zero-size array to reduction operation maximum which has no identity
```
