Zuallererst ist diese Fragenicht das Gleiche wiedieses.

Das Problem, das ich habe, ist, dass ich beim Versuch, einen DataFrame zu zeichnen, der eine Anzahl NaN in einer Zelle enthält, eine Fehlermeldung erhalte:

C:\>\Python33x86\python.exe
Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas as pd
>>> import numpy as np
>>> import matplotlib.pyplot as plt
>>>
>>> dates = pd.date_range('20131201', periods=5, freq='H')
>>> data = [[1, 2], [4, 5], [9, np.nan], [16, 17], [25, 26]]
>>> df = pd.DataFrame(data, index=dates,
...                       columns=list('AB'))
>>>
>>> print(df.to_string())
                      A   B
2013-12-01 00:00:00   1   2
2013-12-01 01:00:00   4   5
2013-12-01 02:00:00   9 NaN
2013-12-01 03:00:00  16  17
2013-12-01 04:00:00  25  26
>>> df.plot()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1636, in plot_frame
    plot_obj.generate()
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 856, in generate
    self._make_plot()
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1240, in _make_plot
    self._make_ts_plot(data, **self.kwds)
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1321, in _make_ts_plot
    _plot(data[col], i, ax, label, style, **kwds)
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1295, in _plot
    style=style, **kwds)
  File "C:\Python33x86\lib\site-packages\pandas\tseries\plotting.py", line 77, in tsplot
    lines = plotf(ax, *args, **kwargs)
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 4139, in plot
    for line in self._get_lines(*args, **kwargs):
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 319, in _grab_next_args
    for seg in self._plot_args(remaining, kwargs):
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 297, in _plot_args
    x, y = self._xy_from_xy(x, y)
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 216, in _xy_from_xy
    by = self.axes.yaxis.update_units(y)
  File "C:\Python33x86\lib\site-packages\matplotlib\axis.py", line 1337, in update_units
    converter = munits.registry.get_converter(data)
  File "C:\Python33x86\lib\site-packages\matplotlib\units.py", line 137, in get_converter
    xravel = x.ravel()
  File "C:\Python33x86\lib\site-packages\numpy\ma\core.py", line 3969, in ravel
    r._mask = ndarray.ravel(self._mask).reshape(r.shape)
  File "C:\Python33x86\lib\site-packages\pandas\core\series.py", line 981, in reshape
    return ndarray.reshape(self, newshape, order)
TypeError: an integer is required

Der obige Code funktioniert, wenn ich die np.NaN durch eine Zahl wie "2.3" ersetze.

Das Plotten als zwei separate Serien funktioniert auch nicht (es schlägt fehl, wenn ich die Serie mit dem NaN zum Plot hinzufüge):

C:\>\Python33x86\python.exe
Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas as pd
>>> import numpy as np
>>> import matplotlib.pyplot as plt
>>>
>>> dates = pd.date_range('20131201', periods=5, freq='H')
>>> data = [[1, 2], [4, 5], [9, np.nan], [16, 17], [25, 26]]
>>> df = pd.DataFrame(data, index=dates,
...                       columns=list('AB'))
>>>
>>> print(df.to_string())
                      A   B
2013-12-01 00:00:00   1   2
2013-12-01 01:00:00   4   5
2013-12-01 02:00:00   9 NaN
2013-12-01 03:00:00  16  17
2013-12-01 04:00:00  25  26
>>> df['A'].plot(label='This is A', style='k')
<matplotlib.axes.AxesSubplot object at 0x02ACFF90>
>>> df['B'].plot(label='This is B', style='g')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1730, in plot_series
    plot_obj.generate()
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 856, in generate
    self._make_plot()
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1240, in _make_plot
    self._make_ts_plot(data, **self.kwds)
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1311, in _make_ts_plot
    _plot(data, 0, ax, label, self.style, **kwds)
  File "C:\Python33x86\lib\site-packages\pandas\tools\plotting.py", line 1295, in _plot
    style=style, **kwds)
  File "C:\Python33x86\lib\site-packages\pandas\tseries\plotting.py", line 77, in tsplot
    lines = plotf(ax, *args, **kwargs)
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 4139, in plot
    for line in self._get_lines(*args, **kwargs):
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 319, in _grab_next_args
    for seg in self._plot_args(remaining, kwargs):
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 297, in _plot_args
    x, y = self._xy_from_xy(x, y)
  File "C:\Python33x86\lib\site-packages\matplotlib\axes.py", line 216, in _xy_from_xy
    by = self.axes.yaxis.update_units(y)
  File "C:\Python33x86\lib\site-packages\matplotlib\axis.py", line 1337, in update_units
    converter = munits.registry.get_converter(data)
  File "C:\Python33x86\lib\site-packages\matplotlib\units.py", line 137, in get_converter
    xravel = x.ravel()
  File "C:\Python33x86\lib\site-packages\numpy\ma\core.py", line 3969, in ravel
    r._mask = ndarray.ravel(self._mask).reshape(r.shape)
  File "C:\Python33x86\lib\site-packages\pandas\core\series.py", line 981, in reshape
    return ndarray.reshape(self, newshape, order)
TypeError: an integer is required

Wenn ich dies jedoch direkt mit Matplotlibs Pyplot plot () mache, anstatt die plot () - Funktion von Pandas zu verwenden, funktioniert es:

C:\>\Python33x86\python.exe
Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas as pd
>>> import numpy as np
>>> import matplotlib.pyplot as plt
>>> dates = pd.date_range('20131201', periods=5, freq='H')
>>> plt.plot(dates, [1, 4, 9, 16, 25], 'k', dates, [2, 5, np.NAN, 17, 26], 'g')
[<matplotlib.lines.Line2D object at 0x03E98650>, <matplotlib.lines.Line2D object at 0x040929B0>]
>>> plt.show()
>>>

Es scheint also, dass ich eine Problemumgehung habe, aber da ich große DataFrames plotte, würde ich lieber die plot () -Methode von Pandas verwenden, was praktischer ist. Ich habe versucht, dem Stack-Trace zu folgen, aber nach einer Weile wird es kompliziert (ich kenne mich nicht mehr mit Pandas-, Numpy- und Matplotlib-Quellcode aus). Mache ich etwas falsch oder ist dies ein möglicher Fehler in Pandas Handlung ()?

Danke für deine Hilfe!

Ich habe es sowohl unter Windows x86 als auch unter Linux AMD64 mit den gleichen Ergebnissen mit den folgenden Versionen versucht:

Python 3.3.2Pandas 0.12.0Matplotlib 1.3.1Numpy 1.7.1