居中TickLabels

有时将ticklabels置于中心是件好事。 Matplotlib目前将标签与刻度线关联，标签可以使用水平对齐属性对齐“中心”，“左”或“右”：

  1. ax.xaxis.set_tick_params(horizontalalignment='right')

但这并没有帮助将标签置于刻度之间。一种解决方案是“伪造它”。 使用次要刻度在主要刻度之间放置一个刻度。这是一个标记月份的示例，以ticks为中心。

居中TickLabels示例

  1. import numpy as np
  2. import matplotlib.cbook as cbook
  3. import matplotlib.dates as dates
  4. import matplotlib.ticker as ticker
  5. import matplotlib.pyplot as plt
  7. # load some financial data; apple's stock price
  8. with cbook.get_sample_data('aapl.npz') as fh:
  9.     r = np.load(fh)['price_data'].view(np.recarray)
  10. r = r[-250:]  # get the last 250 days
  11. # Matplotlib works better with datetime.datetime than np.datetime64, but the
  12. # latter is more portable.
  13. date = r.date.astype('O')
  15. fig, ax = plt.subplots()
  16. ax.plot(date, r.adj_close)
  18. ax.xaxis.set_major_locator(dates.MonthLocator())
  19. ax.xaxis.set_minor_locator(dates.MonthLocator(bymonthday=15))
  21. ax.xaxis.set_major_formatter(ticker.NullFormatter())
  22. ax.xaxis.set_minor_formatter(dates.DateFormatter('%b'))
  24. for tick in ax.xaxis.get_minor_ticks():
  25.     tick.tick1line.set_markersize(0)
  26.     tick.tick2line.set_markersize(0)
  27.     tick.label1.set_horizontalalignment('center')
  29. imid = len(r) // 2
  30. ax.set_xlabel(str(date[imid].year))
  31. plt.show()

下载这个示例