Sorry if this is a repost; I'm sure this question gets asked often but I couldn't find exactly what I was after in the search. I'm trying to write a scientific plotting program in matplotlib (using python 2.7) and I'm having trouble getting it to recognise LaTeX code the way I expect.
On the matplotlib site, there is an example which works perfectly on my machine (Ubuntu 12.04):
from matplotlib import rc
from numpy import arange, cos, pi
from matplotlib.pyplot import figure, axes, plot, xlabel, ylabel, title, \
grid, savefig, show
rc('text', usetex=True)
rc('font', family='serif')
figure(1, figsize=(6,4))
ax = axes([0.1, 0.1, 0.8, 0.7])
t = arange(0.0, 1.0+0.01, 0.01)
s = cos(2*2*pi*t)+2
plot(t, s)
xlabel(r'\textbf{time (s)}')
ylabel(r'\textit{voltage (mV)}',fontsize=16)
title(r"\TeX\ is Number $\displaystyle\sum_{n=1}^\infty\frac{-e^{i\pi}}{2^n}$!",
fontsize=16, color='r')
grid(True)
savefig('tex_demo')
show()
But when I try and apply the concepts from this to my existing code, things go awry. My code is reading in values from a text file to use as strings for the titles and axes for a series of subplots. the text file looks like this only one line break per line in the original:
Example \texit{plot title}
x label
y label
So I'm expecting everything to be ordinary except "plot title", which should be italic. Here is the function that I have written:
from matplotlib import rc
...
def plot_graphic(formatting_file):
rc('text', usetex=True)
rc('font', family='serif')
formatting = open(formatting_file)
data = formatting.readlines()
title_text = data[0]
sup_title_size = 20
title_size = int(0.75*sup_title_size)
x_axis_label = data[1]
y_axis_label = data[2]
plt.subplot(224)
plt.plot(n.x, o, n.x, s, "r")
plt.title("Original and Smoothed Data", fontsize=title_size)
plt.xlabel(x_axis_label)
plt.ylabel(y_axis_label)
plt.subplot(221)
plt.plot(n.x, o)
plt.title("Original Data", fontsize=title_size)
plt.xlabel(x_axis_label)
plt.ylabel(y_axis_label)
plt.subplot(223)
plt.plot(n.x, s, "r")
plt.title("Smoothed Data", fontsize=title_size)
plt.xlabel(x_axis_label)
plt.ylabel(y_axis_label)
plt.subplot(222)
plt.plot(gx, gy, "k.-")
plt.title("Smoothing Window", fontsize=title_size)
plt.xlabel(x_axis_label)
plt.ylabel("Window Function")
plt.suptitle(title_text, fontsize=sup_title_size)
plt.subplots_adjust(wspace=0.3)
plt.show()
formatting.close()
Where "formatting_file" is a string (path to the file with the above contents), and everything works as expected without the Tex formatting attempt (if I remove the lines starting with rc). When I run this, however, I get a wall of tracebacks ending with:
RuntimeError: LaTeX was not able to process the following string:
''
Here is the full report generated by LaTeX:
This is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian)
entering extended mode
(./65d362bbbe189488f3ed27a3ef3526ff.tex
LaTeX2e <2009/09/24>
Babel <v3.8l> and hyphenation patterns for english, usenglishmax, dumylang, noh
yphenation, loaded.
(/usr/share/texmf-texlive/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/usr/share/texmf-texlive/tex/latex/base/size10.clo))
(/usr/share/texmf-texlive/tex/latex/type1cm/type1cm.sty)
(/usr/share/texmf-texlive/tex/latex/psnfss/helvet.sty
(/usr/share/texmf-texlive/tex/latex/graphics/keyval.sty))
(/usr/share/texmf-texlive/tex/latex/psnfss/courier.sty)
(/usr/share/texmf-texlive/tex/latex/base/textcomp.sty
(/usr/share/texmf-texlive/tex/latex/base/ts1enc.def))
(/usr/share/texmf-texlive/tex/latex/geometry/geometry.sty
(/usr/share/texmf-texlive/tex/generic/oberdiek/ifpdf.sty)
(/usr/share/texmf-texlive/tex/generic/oberdiek/ifvtex.sty)
Package geometry Warning: Over-specification in `h'-direction.
`width' (5058.9pt) is ignored.
Package geometry Warning: Over-specification in `v'-direction.
`height' (5058.9pt) is ignored.
) (./65d362bbbe189488f3ed27a3ef3526ff.aux)
(/usr/share/texmf-texlive/tex/latex/base/ts1cmr.fd)
(/usr/share/texmf-texlive/tex/latex/psnfss/ot1pnc.fd)
*geometry auto-detecting driver*
*geometry detected driver: dvips*
(./65d362bbbe189488f3ed27a3ef3526ff.aux) )
No pages of output.
Transcript written on 65d362bbbe189488f3ed27a3ef3526ff.log.
It boils down to this: I don't have a lot of experience with LaTeX, but I'm trying to learn, so I don't understand these errors. I don't understand why my code doesn't work when it doesn't seem to be an awful lot different from the example which does. For reference, I have also tried this on an x86 Windows 7 machine with the same result.
What am I missing?
EDIT:
I suppose the code snippet I supplied for my example is excessively long. A shorter, simpler version would be along these lines:
import matplotlib.pyplot as plt
from matplotlib import rc
rc('text', usetex=True)
rc('font', family='serif')
data = ["Example \texit{plot title}\n", "x label", "y label"]
title_text = data[0]
x_axis_label = data[1]
y_axis_label = data[2]
plt.plot([1,2,3,4],[1,2,3,4])
plt.title(title_text)
plt.xlabel(x_axis_label)
plt.ylabel(y_axis_label)
plt.show()
Best Answer
I think your problem is newline characters read in from the file. Try removing them with
rstrip(). That will fix your short example. Maybe something like this for your longer code:By the way, matplotlib 1.2 added a pgf backend, so that may be something you want to look into.