在第二行显示年份的一个选项是使用主要和次要刻度标签。
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.dates import MonthLocator, YearLocator, DateFormatter
ix = pd.date_range('1/1/2017', '11/1/2018', freq='D')
vals = np.random.randn(len(ix))
s = pd.DataFrame({'Values': vals}, index=ix)
fig, ax = plt.subplots(figsize=[8,6])
ax.plot(s, lw=1)
ax.xaxis.set_major_locator(YearLocator())
ax.xaxis.set_major_formatter(DateFormatter("\n%Y"))
ax.xaxis.set_minor_locator(MonthLocator((1,4,7,10)))
ax.xaxis.set_minor_formatter(DateFormatter("%b"))
plt.show()
如果您需要次要刻度用于其他用途,则以下内容将单独格式化主要刻度 - 具有相同的结果。在这里,您将使用 FuncFormatter 根据月份确定格式。
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.dates import MonthLocator, DateFormatter
from matplotlib.ticker import FuncFormatter
ix = pd.date_range('1/1/2017', '11/1/2018', freq='D')
vals = np.random.randn(len(ix))
s = pd.DataFrame({'Values': vals}, index=ix)
fig, ax = plt.subplots(figsize=[8,6])
ax.plot(s, lw=1)
monthfmt = DateFormatter("%b")
yearfmt = DateFormatter("%Y")
def combinedfmt(x,pos):
string = monthfmt(x)
if string == "Jan":
string += "\n" + yearfmt(x)
return string
ax.xaxis.set_major_locator(MonthLocator((1,4,7,10)))
ax.xaxis.set_major_formatter(FuncFormatter(combinedfmt))
plt.show()
两种情况的结果是相同的:
![enter image description here](https://i.stack.imgur.com/cka0u.png)