matplotlib pdf backend, usetex and Times font doesn't work

[joergdietrich]

The following example

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

mpl.rcdefaults()
# This doesn't work
mpl.rcParams['font.serif'] = "Times, serif"
# This does
# mpl.rcParams['font.serif'] = "Bitstream Vera Serif, serif"
mpl.rcParams['text.usetex'] = "true"

x = np.random.normal(size=100)
y = np.random.normal(size=100)
plt.scatter(x, y)
plt.xlabel("$\gamma$")
plt.savefig("foo.png")
print("foo.png saved")
plt.savefig("bar.pdf")
print("bar.pdf saved")

produces

$ python latex_plots.py 
foo.png saved
Traceback (most recent call last):
  File "latex_plots.py", line 20, in <module>
    plt.savefig("bar.pdf")
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/pyplot.py", line 577, in savefig
    res = fig.savefig(*args, **kwargs)
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/figure.py", line 1476, in savefig
    self.canvas.print_figure(*args, **kwargs)
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/backend_bases.py", line 2211, in print_figure
    **kwargs)
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/backends/backend_pdf.py", line 2491, in print_pdf
    file.close()
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/backends/backend_pdf.py", line 525, in close
    self.writeFonts()
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/backends/backend_pdf.py", line 621, in writeFonts
    self.dviFontInfo[filename])
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/backends/backend_pdf.py", line 686, in embedTeXFont
    t1font = t1font.transform(fontinfo.effects)
  File "/home/joerg/applications/anaconda3/lib/python3.4/site-packages/matplotlib/type1font.py", line 336, in transform
    value = value.encode('latin-1')
AttributeError: 'bytes' object has no attribute 'encode'

Note that text.usetex needs to be true, a LaTeX symbol like \gamma has to be used, the font needs to be Times, and the backend pdf for this example to fail.

[joergdietrich]

This is with
matplotlib 1.4.3 np19py34_1

[ccordoba12]

This seems to be a bug in Matplotlib.

@tacaswell, is this problem known to you?

[tacaswell]

Does indeed look like a mpl bug and I do not recognize this off the top of my head.

[tacaswell]

@ccordoba12 This issue can be closed as fix required upstream.

[ccordoba12]

Great!! Thanks for the prompt answer :-)

[rajaditya-m]

Hi is this issue fixed? I updates Anaconda right now and I am still getting this issue.

[tacaswell]

Should have been fixed by matplotlib/matplotlib#4522 which should be included in mpl 1.5

[rajaditya-m]

HI Thomas,

I just updated Matplotlib explicitly using conda update and the issue is still persisting. Will it be in the next release?

[tacaswell]

I can not reproduce this with mpl 1.5.1 + python 3.5. You may have found a new bug or are not running in the enviroment you think you are using.

Can you please provide (in a new issue) a minimal script to reproduce along with the trace back you are seeing, mpl version, python version, and OS?