6

I'm trying to generate a text box with lines of LaTeX code correctly aligned in a matplotlib frame. I tried using the format alignment method (ie: {:<11}) but it does not seem to work on math mode.

Here's the output I get:

enter image description here

where the = symbols should all be aligned to the right (see MWE below).

How can I produce such a text box with the = signs correctly aligned?

MWE:

(Never mind the weird figure proportions and text box placing, this is part of a much larger code which I cropped to generate this MWE)

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)
Gabriel
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1 Answers1

5

You can use the eqnarray enivironment as described here.

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)

Alternative solution using align environment:

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)
Community
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Benjamin
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  • Thanks you Benjamin! This code crashes with the error: `LaTeX was not able to process the following string:'lp' Here is the full report generated by LaTeX: `. Unfortunately there is nothing below that last line. Based on this question http://stackoverflow.com/q/11354149/1391441 it looks like I'm missing some LaTeX pakage. This means this answer adds a dependency to the code, which is not ideal. I'll try to figure out which package that is. – Gabriel May 28 '15 at 20:29
  • Yep, I'm missing `type1cm.sty` which apparently is present in `texlive-latex-extra`. If possible I'd prefer to avoid adding this dependency to the code, but if no better answer is given, I'll mark this one as accepted with that caveat. – Gabriel May 28 '15 at 20:37
  • I already tried to minimize the dependencies by using `eqnarray` personally I would prefer to use the `align` environment. But maybe this solution is compatible with the packages you have installed. – Benjamin May 28 '15 at 20:55
  • 1
    @Gabriel That package seems to be a [known issue](http://matplotlib.org/users/usetex.html#possible-hangups): `On Ubuntu and Gentoo, the base texlive install does not ship with the type1cm package.` – Luis Aug 19 '16 at 13:06