Python 在 matplotlib 图中使用 Pandas 数据帧索引作为 x 轴的值
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/22356881/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Using a Pandas dataframe index as values for x-axis in matplotlib plot
提问by Jason
I have time series in a Pandas dateframewith a number of columns which I'd like to plot. Is there a way to set the x-axis to always use the index from a dateframe?
When I use the .plot()method from Pandas the x-axis is formatted correctly however I when I pass my dates and the column(s) I'd like to plot directly to matplotlib the graph doesn't plot correctly. Thanks in advance.
我在 Pandas 中有时间序列，dateframe其中包含许多我想绘制的列。有没有办法将 x 轴设置为始终使用 a 中的索引dateframe？当我使用.plot()Pandas 中的方法时，x 轴的格式正确，但是当我传递日期和列时，我想直接绘制到 matplotlib 中，图表绘制不正确。提前致谢。
plt.plot(site2.index.values, site2['Cl'])
plt.show()
FYI: site2.index.valuesproduces this (I've cut out the middle part for brevity):
仅供参考：site2.index.values产生这个（为简洁起见，我已经剪掉了中间部分）：
array([
'1987-07-25T12:30:00.000000000+0200',
'1987-07-25T16:30:00.000000000+0200',
'2010-08-13T02:00:00.000000000+0200',
'2010-08-31T02:00:00.000000000+0200',
'2010-09-15T02:00:00.000000000+0200'
],
dtype='datetime64[ns]')
采纳答案by Jason
It seems the issue was that I had .values. Without it (i.e. site2.index) the graph displays correctly.
问题似乎是我有.values. 没有它（即site2.index）图形显示正确。
回答by ycy
You can use plt.xticksto set the x-axis
您可以使用plt.xticks来设置 x 轴
try:
尝试：
plt.xticks( site2['Cl'], site2.index.values ) # location, labels
plt.plot( site2['Cl'] )
plt.show()
see the documentation for more details: http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.xticks
有关更多详细信息，请参阅文档：http: //matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.xticks
