无法在matplotlib x轴上显示dateindex

Question

我试图从pandas数据帧构建x轴为dateIndex的matplotlib图表。我试图模仿matplotlib的一些例子，但没有成功。xaxis记号和标签永远不会出现。你知道吗

我认为matplotlib可能没有正确地消化pandas索引，所以我用matplotlibdate2num帮助函数将其转换为序号，但得到了相同的结果。你知道吗

# https://matplotlib.org/api/dates_api.html
# https://matplotlib.org/examples/api/date_demo.html

import datetime as dt

import matplotlib.dates as mdates
import matplotlib.cbook as cbook

import matplotlib.dates as mpd


years = mdates.YearLocator()   # every year
months = mdates.MonthLocator()  # every month
yearsFmt = mdates.DateFormatter('%Y')


majorLocator = years
majorFormatter = yearsFmt #FormatStrFormatter('%d')
minorLocator = months


y1 = np.arange(100)*0.14+1
y2 = -(np.arange(100)*0.04)+12

"""neither of these indices works"""
x = pd.date_range(start='4/1/2012', periods=len(y1))
#x = map(mpd.date2num, pd.date_range(start='4/1/2012', periods=len(y1)))

fig, ax = plt.subplots()
ax.plot(x,y1)
ax.plot(x,y2)

ax.xaxis.set_major_locator(years)
ax.xaxis.set_major_formatter(yearsFmt)
ax.xaxis.set_minor_locator(months)

datemin = x[0]   
datemax = x[-1]  
ax.set_xlim(datemin, datemax)
fig.autofmt_xdate()
plt.show()

Answer 1

您可以使用pd.DataFrame.plot来处理其中的大部分

df = pd.DataFrame(dict(
    y1=y1, y2=y2
), index=x)

df.plot()