试图使用matplotlib Latex保存postscript时出错

Question

当我尝试将python图形保存为PostScript时，当我使用Latex和xfrac包时，我得到了一个错误，我可以以其他格式保存这个图形，但不能用PostScript保存。

这是我使用的代码..。

import matplotlib
import matplotlib.pyplot as plt

# Use LaTeX for rendering
matplotlib.rcParams["text.usetex"] = True
# load the xfrac package
matplotlib.rcParams["text.latex.preamble"].append(r'\usepackage{xfrac}')

fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot([0,1],[1,0])
ax.text(.5, .5, r'$\sfrac{1}{2}$')
plt.savefig('111.ps')

这是我得到的错误(如果我不使用xfrac包，我就不会得到一个错误)

LaTeX was not able to process your file:    
Here is the full report generated by LaTeX: 

This is pdfTeX, Version 3.14159265-2.6-1.40.15 (TeX Live 2014) (preloaded format=latex)
 restricted \write18 enabled.
entering extended mode
(/tmp/tmp0Nr4Ze.tex
LaTeX2e <2014/05/01>
Babel <3.9k> and hyphenation patterns for 79 languages loaded.
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/base/size10.clo))
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/type1cm/type1cm.sty)
 (/home/users/MyName/Local/Latex/texmf-dist/tex/latex/psnfss/helvet.sty
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/graphics/keyval.sty)
) (/home/users/MyName/Local/Latex/texmf-dist/tex/latex/psnfss/courier.sty
) (/home/users/MyName/Local/Latex/texmf-dist/tex/latex/base/textcomp.sty
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/base/ts1enc.def))
(/home/users/MyName/texmf/tex/latex/xfrac.sty
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/amsmath/amstext.sty
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/amsmath/amsgen.sty))

(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/graphics/graphicx.st
y
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/graphics/graphics.st
y (/home/users/MyName/Local/Latex/texmf-dist/tex/latex/graphics/trig.sty)

(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/latexconfig/graphics
.cfg)
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/graphics/dvips.def))
) (/home/users/MyName/texmf/tex/latex/l3keys2e.sty
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/l3kernel/expl3.sty
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/l3kernel/expl3-code.
tex
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/etex-pkg/etex.sty))
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/l3kernel/l3unicode-d
ata.def)
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/l3kernel/l3dvips.def
))) (/home/users/MyName/texmf/tex/latex/xparse.sty)
(/home/users/MyName/texmf/tex/latex/xtemplate.sty))
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/geometry/geometry.st
y
(/home/users/MyName/Local/Latex/texmf-dist/tex/generic/oberdiek/ifpdf.sty
)
(/home/users/MyName/Local/Latex/texmf-dist/tex/generic/oberdiek/ifvtex.st
y)
(/home/users/MyName/Local/Latex/texmf-dist/tex/generic/ifxetex/ifxetex.st
y)

Package geometry Warning: Over-specification in `h'-direction.
    `width' (614.295pt) is ignored.


Package geometry Warning: Over-specification in `v'-direction.
    `height' (794.96999pt) is ignored.

) (/home/users/MyName/Local/Latex/texmf-dist/tex/latex/psfrag/psfrag.sty)


! LaTeX Error: Option clash for package graphicx.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.13 \usepackage
                {color}
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/graphics/color.sty
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/latexconfig/color.cf
g)
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/graphics/dvipsnam.de
f))
No file tmp0Nr4Ze.aux.
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/base/ts1cmr.fd)
(/home/users/MyName/Local/Latex/texmf-dist/tex/latex/psnfss/ot1pnc.fd)
*geometry* detected driver: dvips
<tmp0Nr4Ze.eps> [1] (./tmp0Nr4Ze.aux) )
(see the transcript file for additional information)
Output written on tmp0Nr4Ze.dvi (1 page, 3368 bytes).
Transcript written on tmp0Nr4Ze.log.

有人知道怎么解决这个问题吗？

编辑

现在我发现，如果我试图将它保存为pgf ( LaTeX PGF图)

我知道这个错误

Error processing '\(\displaystyle \sfrac{\tau_{peel}}{\tau_{m}}\)'
LaTeX Output:
! Undefined control sequence.
<argument> ...}\selectfont \(\displaystyle \sfrac 
                                                  {\tau _{peel}}{\tau _{m}}\)
<*> ...splaystyle \sfrac{\tau_{peel}}{\tau_{m}}\)}

No pages of output.
Transcript written on texput.log.

EDIT2:

我有时会犯这个错误

dvipng warning: No image output from inclusion of raw PostScript GPL Ghostscript 9.05: Unrecoverable error, exit code 1

所以我更新了Ghostscript，现在我得到了这个错误:-)

dvipng warning: No image output from inclusion of raw PostScript GPL Ghostscript 9.14: Unrecoverable error, exit code 1

Answer 1

在本例中，为了输出ps，需要将dvips选项传递给graphicx

\usepackage[dvips]{graphicx}

剧本应该是：

import matplotlib
import matplotlib.pyplot as plt

# Use LaTeX for rendering
matplotlib.rcParams["text.usetex"] = True
# load the xfrac package
matplotlib.rcParams["text.latex.preamble"].append(r'\usepackage[dvips]{graphicx}\usepackage{xfrac}')

fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot([0,1],[1,0])
ax.text(.5, .5, r'$\sfrac{1}{2}$')
plt.savefig('111.ps')

graphicx可能是由matplotlib加载的，为了输出ps，matplotlib使用dvips驱动程序，因此必须将该选项传递给graphicx。

不过，我认为用原始代码输出pdf并用ghostscript将其转换为ps更容易。