Python Matplotlib如何设置多行不同旋转方向的X轴刻度标签？

方案一：子图分层实现独立刻度控制 #

通过创建多个子图分别承载不同行的刻度，实现旋转角度的独立控制：

• 主图负责绘制数据，隐藏自身X轴刻度
• 子图1放置时间刻度，设置垂直旋转
• 子图2放置星期+日期标签，保持水平显示

import matplotlib.pyplot as plt
import numpy as np
from datetime import datetime

# 模拟数据
dates = [datetime(2024, 5, 1, h) for h in range(9, 18)] + [datetime(2024, 5, 2, h) for h in range(9, 18)]
times = [d.strftime('%I:%M %p') for d in dates]
days = [d.strftime('%A') for d in dates]
date_strs = [d.strftime('%d %b %y') for d in dates]
values = np.random.rand(len(dates))

# 创建画布与分层子图
fig, (ax_day, ax_time, ax_main) = plt.subplots(3, 1, figsize=(12, 6), 
                                               gridspec_kw={'height_ratios': [0.5, 0.5, 8]})

# 主图绘制数据并隐藏默认X轴刻度
ax_main.plot(dates, values)
ax_main.set_xticks([])

# 时间刻度子图：垂直旋转标签
ax_time.set_xticks(dates)
ax_time.set_xticklabels(times, rotation=90, ha='center')
ax_time.tick_params(axis='x', length=0)  # 隐藏刻度线
ax_time.set_yticks([])  # 隐藏Y轴元素

# 星期+日期子图：仅每日首个刻度显示内容
day_labels = []
for d, day, date in zip(dates, days, date_strs):
    day_labels.append(f'{day}\n{date}' if d.hour == 9 else '')
ax_day.set_xticks(dates)
ax_day.set_xticklabels(day_labels, ha='center')
ax_day.tick_params(axis='x', length=0)
ax_day.set_yticks([])

# 对齐所有子图的X轴范围
ax_day.set_xlim(ax_main.get_xlim())
ax_time.set_xlim(ax_main.get_xlim())

plt.tight_layout()
plt.show()

方案二：自定义刻度文本艺术家（Artist） #

直接在轴上添加独立的Text对象，精准控制每个标签的旋转角度与位置：

• 获取主图X轴刻度位置，隐藏默认刻度
• 分别添加垂直旋转的时间标签、水平显示的星期日期标签

import matplotlib.pyplot as plt
import numpy as np
from datetime import datetime

# 模拟数据
dates = [datetime(2024, 5, 1, h) for h in range(9, 18)] + [datetime(2024, 5, 2, h) for h in range(9, 18)]
times = [d.strftime('%I:%M %p') for d in dates]
days = [d.strftime('%A') for d in dates]
date_strs = [d.strftime('%d %b %y') for d in dates]
values = np.random.rand(len(dates))

fig, ax = plt.subplots(figsize=(12, 6))
ax.plot(dates, values)

# 获取刻度位置并隐藏默认刻度
xticks = ax.get_xticks()
ax.set_xticks([])

# 添加垂直旋转的时间标签
for x, time in zip(xticks, times):
    ax.text(x, ax.get_ylim()[0] - 0.1, time, rotation=90, ha='center', va='top', transform=ax.get_xaxis_transform())

# 添加水平显示的星期+日期标签
for x, d, day, date in zip(xticks, dates, days, date_strs):
    if d.hour == 9:
        ax.text(x, ax.get_ylim()[0] - 0.25, f'{day}\n{date}', ha='center', va='top', transform=ax.get_xaxis_transform())

plt.subplots_adjust(bottom=0.2)
plt.show()

内容的提问来源于stack exchange，提问作者Rowan Hayes