将标签居中在刻度之间

刻度标签相对于其关联的刻度对齐。可以使用水平对齐属性控制对齐方式“居中”、“左”或“右”。

for label in ax.get_xticklabels():
    label.set_horizontalalignment('right')

但是，没有直接的方法可以将标签居中在刻度之间。为了模拟这种行为，可以在主要刻度之间的次刻度上放置标签，并隐藏主要刻度标签和次刻度。

以下是一个将月份标签居中在刻度之间的示例。

import matplotlib.pyplot as plt

import matplotlib.cbook as cbook
import matplotlib.dates as dates
import matplotlib.ticker as ticker

# Load some financial data; Google's stock price
r = cbook.get_sample_data('goog.npz')['price_data']
r = r[-250:]  # get the last 250 days

fig, ax = plt.subplots()
ax.plot(r["date"], r["adj_close"])

ax.xaxis.set_major_locator(dates.MonthLocator())
# 16 is a slight approximation since months differ in number of days.
ax.xaxis.set_minor_locator(dates.MonthLocator(bymonthday=16))

ax.xaxis.set_major_formatter(ticker.NullFormatter())
ax.xaxis.set_minor_formatter(dates.DateFormatter('%b'))

# Remove the tick lines
ax.tick_params(axis='x', which='minor', tick1On=False, tick2On=False)

# Align the minor tick label
for label in ax.get_xticklabels(minor=True):
    label.set_horizontalalignment('center')
imid = len(r) // 2
ax.set_xlabel(str(r["date"][imid].item().year))
plt.show()