在matplotlib文本框中对齐LaTeX数学文本

Question

我正在尝试生成一个文本框，其中包含在matplotlib框架中正确对齐的LaTeX代码行。我尝试使用格式对齐方法（即：{:<11}）但它似乎不适用于数学模式。

这是我得到的输出：

其中=符号应全部与右侧对齐（请参阅下面的MWE）。

如何生成这样一个正确对齐=符号的文本框？

MWE ：

（别介意奇怪的图形比例和文本框放置，这是我为了生成这个MWE而裁剪的更大代码的一部分）

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
import matplotlib.offsetbox as offsetbox

# Figure top-level container. Weird size is because
# this is part of a larger code.
fig = plt.figure(figsize=(30, 25))
gs = gridspec.GridSpec(10, 12)
ax_t = plt.subplot(gs[4:6, 10:12])

# Some mock values.
cp_r = [0.001, 8.3, 0.18, 15.2, 5000, 0.3]
cp_e = [0.0005, 0.2, 0.11, 0.3, 200, 0.1]

# Remove axis from frame.
ax_t.axis('off')

# Text lines.
text2 = r'{:<11}'.format('$y$') + \
    r'$=\, {} \pm {}$'.format(cp_r[0], cp_e[0])
text3 = r'{:<11}'.format('$log(ret)$') + \
    r'$=\, {} \pm {}$'.format(cp_r[1], cp_e[1])
text4 = r'{:<11}'.format('$A_{{(B-C)}}$') + \
    r'$=\, {} \pm {}$'.format(cp_r[2], cp_e[2])
text5 = r'{:<11}'.format('$(n-N)_o$') + \
    r'$=\, {} \pm {}$'.format(cp_r[3], cp_e[3])
text6 = r'{:<11}'.format('$K_{{\odot}}$') + \
    r'$=\, {} \pm {}$'.format(cp_r[4], cp_e[4])
text7 = r'{:<11}'.format('$d_{{frac}}$') + \
    r'$=\, {} \pm {}$'.format(cp_r[5], cp_e[5])
text = text2 + '\n' + text3 + '\n' + text4 + '\n' + text5 + '\n' + text6 + \
    '\n' + text7

# Draw text box.
ob = offsetbox.AnchoredText(text, pad=1, loc=6, prop=dict(size=13))
ob.patch.set(alpha=0.85)
ax_t.add_artist(ob)

plt.savefig('out.png', dpi=300)

Answer 1

您可以使用here所述的eqnarray enivironment。

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
import matplotlib.offsetbox as offsetbox
from matplotlib import rc

rc('text', usetex=True)

# Figure top-level container. Weird size is because
# this is part of a larger code.
fig = plt.figure(figsize=(30, 25))
gs = gridspec.GridSpec(10, 12)
ax_t = plt.subplot(gs[4:6, 10:12])

# Some mock values.
cp_r = [0.001, 8.3, 0.18, 15.2, 5000, 0.3]
cp_e = [0.0005, 0.2, 0.11, 0.3, 200, 0.1]

# Remove axis from frame.
ax_t.axis('off')

# Text lines.
text1 = r'\begin{eqnarray*} '
text2 = r'y &=& ' + str(cp_r[0]) + '\pm ' + str(cp_e[0]) + '\\\\'
text3 = r'\log(ret) &=& ' + str(cp_r[1]) + '\pm ' + str(cp_e[1]) + '\\\\'
text4 = r'A_{{(B-C)}} &=& ' + str(cp_r[2]) + '\pm ' + str(cp_e[2]) + '\\\\'
text5 = r'(n-N)_o &=& ' + str(cp_r[3]) + '\pm ' + str(cp_e[3]) + '\\\\'
text6 = r'K_{{\odot}} &=& ' + str(cp_r[4]) + '\pm ' + str(cp_e[4]) + '\\\\'
text7 = r'd_{{frac}} &=& ' + str(cp_r[5]) + '\pm ' + str(cp_e[5])
text8 = r'\end{eqnarray*}'
text = text1 + text2 + text3 + text4 + text5 + text6 + text7 + text8

# Draw text box.
ob = offsetbox.AnchoredText(text, pad=1, loc=6, prop=dict(size=13))
ob.patch.set(alpha=0.85)
ax_t.add_artist(ob)

plt.savefig('out.png', dpi=300)

使用align环境的替代解决方案：

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
import matplotlib.offsetbox as offsetbox
custom_preamble = {
    "text.usetex": True,
    "text.latex.preamble": [
        r"\usepackage{amsmath}", # for the align enivironment
        ],
    }
plt.rcParams.update(custom_preamble)

# Figure top-level container. Weird size is because
# this is part of a larger code.
fig = plt.figure(figsize=(30, 25))
gs = gridspec.GridSpec(10, 12)
ax_t = plt.subplot(gs[4:6, 10:12])

# Some mock values.
cp_r = [0.001, 8.3, 0.18, 15.2, 5000, 0.3]
cp_e = [0.0005, 0.2, 0.11, 0.3, 200, 0.1]

# Remove axis from frame.
ax_t.axis('off')

# Text lines.
text1 = r'\begin{align*} '
text2 = r'y &= ' + str(cp_r[0]) + '\pm ' + str(cp_e[0]) + '\\\\'
text3 = r'\log(ret) &= ' + str(cp_r[1]) + '\pm ' + str(cp_e[1]) + '\\\\'
text4 = r'A_{{(B-C)}} &= ' + str(cp_r[2]) + '\pm ' + str(cp_e[2]) + '\\\\'
text5 = r'(n-N)_o &= ' + str(cp_r[3]) + '\pm ' + str(cp_e[3]) + '\\\\'
text6 = r'K_{{\odot}} &= ' + str(cp_r[4]) + '\pm ' + str(cp_e[4]) + '\\\\'
text7 = r'd_{{frac}} &= ' + str(cp_r[5]) + '\pm ' + str(cp_e[5])
text8 = r'\end{align*}'
text = text1 + text2 + text3 + text4 + text5 + text6 + text7 + text8

# Draw text box.
ob = offsetbox.AnchoredText(text, pad=1, loc=6, prop=dict(size=13))
ob.patch.set(alpha=0.85)
ax_t.add_artist(ob)

plt.savefig('out.png', dpi=300)