Using pgfplot externalize with .eps output

Question

I'm trying use to use pgfplot's externalization feature b/c I've got many large plots that I don't want to regenerate every time I typeset my thesis. Other components of my thesis require compile via latex > ps > pdf (i.e. "latex" followed by "dvips" followed by "ps2pdf"), so I'm trying to stick with that. I'm having trouble getting the externalization to work, unfortunately. Here is my minimum example, which I have produced by following the instructions in the pgfplots manual for getting .eps output (pg 240).

\documentclass{article}
\usepackage{pgfplots}
\usetikzlibrary{pgfplots.groupplots}
\usepgfplotslibrary{external}
\tikzexternalize[shell escape=-enable-write18]
\tikzset{external/system call={latex \tikzexternalcheckshellescape -halt-on-error -interaction=batchmode -jobname "\image" "\texsource" & dvips -o "\image".ps "\image".dvi}}

\begin{document}

\begin{tikzpicture}
\begin{axis}[xlabel=x,ylabel=y]
\addplot[] coordinates{(0,0) (1,2)};
\end{axis}
\end{tikzpicture}

\end{document}

When I do the compile, the external .dvi and .ps files for the figure are successfully generated and there are no errors, but the figure is absent from the actual compiled document .pdf. The pgfplots manual suggested I would get .eps output, but this doesn't happen (perhaps this is the trouble?). Anyone have any tips for what I'm doing wrong?

Answer 1

It looks like you made two typos in the \tikzset line; changing it to:

\tikzset{external/system call={latex \tikzexternalcheckshellescape -halt-on-error -interaction=batchmode -jobname "\image" "\texsource" && dvips -o "\image".eps "\image".dvi}}

will make the shell command generate an .eps file from each .dvi file after running the latex command to create that .dvi file. (I replaced a .ps in your file with a .eps, and a & with a &&. Interestingly, the & seemed to work in MiKTeX to invoke latex asynchronously; I wonder why it did that? I don't think cmd.exe supports that, though it does support &&.)

But unfortunately none of that seems to help: though I end up with a postscript file for the whole document that includes the contents of the .eps, it doesn't seem to display any of it, though the .eps file renders fine on its own, and I don't get any error messages about it either :-(.

Answer 2

Usually people forget to properly activate unrestricted shell escape:

latex -shell-escape foo.tex