我正在使用Python和Pandas尝试将值绘制为时间的函数（例如，X轴的范围为00:00:00到23:59:59）。我的输入数据包括完整的时间戳和每个时间戳的相应值。
我可以成功地将值绘制为总时间的函数。但是当我从完整的时间戳中提取时间并尝试绘制时间时，我得到如下所示的错误。
我的方法中缺少什么？这是一些示例代码：
import pandas as pd
import matplotlib.pyplot as plt
my_dates = pd.DatetimeIndex(['2015-01-01 01:23:45', '2015-01-01 12:34:56', '2015-01-02 02:45:00', '2015-01-03 01:22:33'])
my_dates = my_dates.tz_localize('UTC')
values = pd.Series([1, 2, 3, 2.5])
time_of_day = pd.Series(my_dates.time)
df = pd.DataFrame({'vals': values, 'tod' : time_of_day}).set_index(my_dates)
print(df)
输入数据现在如下所示：
tod vals
2015-01-01 01:23:45+00:00 01:23:45 1.0
2015-01-01 12:34:56+00:00 12:34:56 2.0
2015-01-02 02:45:00+00:00 02:45:00 3.0
2015-01-03 01:22:33+00:00 01:22:33 2.5
下面的图表可以使用并生成一个作为总时间函数的图表。
fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot_date(x=df.index, y= df.vals, marker='o')
现在我尝试在一天中的时间内绘图并收到错误
fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot_date(x=df.tod, y= df.vals, marker='o')
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
C:\Anaconda3\lib\site-packages\IPython\core\formatters.py in __call__(self, obj)
335 pass
336 else:
--> 337 return printer(obj)
338 # Finally look for special method names
339 method = _safe_get_formatter_method(obj, self.print_method)
C:\Anaconda3\lib\site-packages\IPython\core\pylabtools.py in <lambda>(fig)
205
206 if 'png' in formats:
--> 207 png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
208 if 'retina' in formats or 'png2x' in formats:
209 png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))
C:\Anaconda3\lib\site-packages\IPython\core\pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
115
116 bytes_io = BytesIO()
--> 117 fig.canvas.print_figure(bytes_io, **kw)
118 data = bytes_io.getvalue()
119 if fmt == 'svg':
C:\Anaconda3\lib\site-packages\matplotlib\backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs)
2156 orientation=orientation,
2157 dryrun=True,
-> 2158 **kwargs)
2159 renderer = self.figure._cachedRenderer
2160 bbox_inches = self.figure.get_tightbbox(renderer)
C:\Anaconda3\lib\site-packages\matplotlib\backends\backend_agg.py in print_png(self, filename_or_obj, *args, **kwargs)
519
520 def print_png(self, filename_or_obj, *args, **kwargs):
--> 521 FigureCanvasAgg.draw(self)
522 renderer = self.get_renderer()
523 original_dpi = renderer.dpi
C:\Anaconda3\lib\site-packages\matplotlib\backends\backend_agg.py in draw(self)
467
468 try:
--> 469 self.figure.draw(self.renderer)
470 finally:
471 RendererAgg.lock.release()
C:\Anaconda3\lib\site-packages\matplotlib\artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
57 def draw_wrapper(artist, renderer, *args, **kwargs):
58 before(artist, renderer)
---> 59 draw(artist, renderer, *args, **kwargs)
60 after(artist, renderer)
61
C:\Anaconda3\lib\site-packages\matplotlib\figure.py in draw(self, renderer)
1083 dsu.sort(key=itemgetter(0))
1084 for zorder, a, func, args in dsu:
-> 1085 func(*args)
1086
1087 renderer.close_group('figure')
C:\Anaconda3\lib\site-packages\matplotlib\artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
57 def draw_wrapper(artist, renderer, *args, **kwargs):
58 before(artist, renderer)
---> 59 draw(artist, renderer, *args, **kwargs)
60 after(artist, renderer)
61
C:\Anaconda3\lib\site-packages\matplotlib\axes\_base.py in draw(self, renderer, inframe)
2108
2109 for zorder, a in dsu:
-> 2110 a.draw(renderer)
2111
2112 renderer.close_group('axes')
C:\Anaconda3\lib\site-packages\matplotlib\artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
57 def draw_wrapper(artist, renderer, *args, **kwargs):
58 before(artist, renderer)
---> 59 draw(artist, renderer, *args, **kwargs)
60 after(artist, renderer)
61
C:\Anaconda3\lib\site-packages\matplotlib\axis.py in draw(self, renderer, *args, **kwargs)
1112 renderer.open_group(__name__)
1113
-> 1114 ticks_to_draw = self._update_ticks(renderer)
1115 ticklabelBoxes, ticklabelBoxes2 = self._get_tick_bboxes(ticks_to_draw,
1116 renderer)
C:\Anaconda3\lib\site-packages\matplotlib\axis.py in _update_ticks(self, renderer)
955
956 interval = self.get_view_interval()
--> 957 tick_tups = [t for t in self.iter_ticks()]
958 if self._smart_bounds:
959 # handle inverted limits
C:\Anaconda3\lib\site-packages\matplotlib\axis.py in <listcomp>(.0)
955
956 interval = self.get_view_interval()
--> 957 tick_tups = [t for t in self.iter_ticks()]
958 if self._smart_bounds:
959 # handle inverted limits
C:\Anaconda3\lib\site-packages\matplotlib\axis.py in iter_ticks(self)
899 Iterate through all of the major and minor ticks.
900 """
--> 901 majorLocs = self.major.locator()
902 majorTicks = self.get_major_ticks(len(majorLocs))
903 self.major.formatter.set_locs(majorLocs)
C:\Anaconda3\lib\site-packages\matplotlib\dates.py in __call__(self)
864 def __call__(self):
865 'Return the locations of the ticks'
--> 866 self.refresh()
867 return self._locator()
868
C:\Anaconda3\lib\site-packages\matplotlib\dates.py in refresh(self)
881 def refresh(self):
882 'Refresh internal information based on current limits.'
--> 883 dmin, dmax = self.viewlim_to_dt()
884 self._locator = self.get_locator(dmin, dmax)
885
C:\Anaconda3\lib\site-packages\matplotlib\dates.py in viewlim_to_dt(self)
625 def viewlim_to_dt(self):
626 vmin, vmax = self.axis.get_view_interval()
--> 627 return num2date(vmin, self.tz), num2date(vmax, self.tz)
628
629 def _get_unit(self):
C:\Anaconda3\lib\site-packages\matplotlib\dates.py in num2date(x, tz)
343 tz = _get_rc_timezone()
344 if not cbook.iterable(x):
--> 345 return _from_ordinalf(x, tz)
346 else:
347 x = np.asarray(x)
C:\Anaconda3\lib\site-packages\matplotlib\dates.py in _from_ordinalf(x, tz)
233 dt = datetime.datetime(
234 dt.year, dt.month, dt.day, int(hour), int(minute), int(second),
--> 235 microsecond, tzinfo=UTC).astimezone(tz)
236
237 if microsecond > 999990: # compensate for rounding errors
TypeError: tzinfo argument must be None or of a tzinfo subclass, not type 'str'
乍一看，这似乎是matplotlib \ dates.py本身的调用问题？我使用的是Python 3.5.0，matplotlib 1.4.3和pandas 0.17.0。
如何更改我的方法以获取我正在寻找的图表？谢谢！