如何使用Matplotlib仅偏移单个坐标轴刻度解决重叠问题

问题描述 #

我用Matplotlib绘制图表时，自定义了部分坐标轴刻度，但出现了刻度标签重叠的情况。尝试在刻度标签字符串末尾添加空格来调整间距，却发现所有空格都被忽略了。以下是我试过但无效的代码：

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt

rc_fonts = {
   'text.usetex': True,
   'font.size': 20,
   'font.family': 'serif',
   'font.serif': 'cm'
}
mpl.rcParams.update(rc_fonts)

x = np.linspace(0, 1, 100, endpoint=True)
y = x**2

labels = ['0',r'$\varepsilon$', '1']
tested_labels1 = ['0',r'$\varepsilon$   ', '1']
tested_labels2 = ['0',r'$\varepsilon$\\ \\ \\ \\qquad', '1']
tested_labels3 = ['0',r'$\varepsilon\qquad$   ', '1']
x_labels = [0, 0.03, 1]

fig, ax = plt.subplots()
ax.plot(x, y)
ax.set_yticks(x_labels, labels)
# 以下尝试均无效——空格被忽略
#ax.set_yticks(x_labels, tested_labels1)
#ax.set_yticks(x_labels, tested_labels2)
#ax.set_yticks(x_labels, tested_labels3)

plt.show()

解决方案 #

在Matt Pitkin的帮助下，我找到了可行的解决方法（虽然不像加空格那么简便，但确实有效），具体代码如下：

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt

rc_fonts = {
    'text.usetex': True,
    'font.size': 20,
    'font.family': 'serif',
    'font.serif': 'cm'
}
mpl.rcParams.update(rc_fonts)

x = np.linspace(0, 1, 100, endpoint=True)
y = x**2

labels = ['0',r'$\varepsilon$', '1']
x_labels = [0, 0.03, 1]

fig, ax = plt.subplots()
ax.plot(x, y)
ax.set_yticks(x_labels, labels)

dx = -0.15; dy = 0. 
offset = mpl.transforms.ScaledTranslation(dx, dy, fig.dpi_scale_trans)
ax.yaxis.get_majorticklabels()[1].set_transform(ax.yaxis.get_majorticklabels()[1].get_transform() + offset)

plt.show()

内容的提问来源于stack exchange，提问作者Hedwin