Why does my Mathematica figure not work with PSFrag?

Question

I created an image in Mathematica with some labels that, for some reason, refuse to be substituted when using PSFrag.

Specifically, the Mathematica code

image = Plot[Sin[x], {x, 0, 2 π}, PlotLabel-> "label"]
Export[NotebookDirectory<>"image.eps",image]

will create the image

The following PSFrag code should, in principle, substitute the label label with a nicely formatted $\sin(x)$:

\documentclass{article}
\usepackage{graphicx}
\usepackage{psfrag}

\begin{document}

  \psfrag{label}{$\sin(x)$}
  \includegraphics[width=\textwidth]{image.eps}

\end{document}

Indeed, a very similar version will work on the example.eps image provided by the PSFrag package in its documentation. However, the label is not replaced by my dvips driver. What is going wrong?

Answer 1

This turns out to be the fault of Mathematica's export protocol to EPS. If you inspect such a file directly in a text editor, the code corresponding to the label has been split up into single letters:

(l) N
P
p
3 10.5 m
(a) N
P
p
7.797 10.5 m
(b) N
P
p
13.203 10.5 m
(e) N
P
p
18 10.5 m
(l) N

That is, the string (label), which is what PSFrag hunts for, has been split into the five different single-character strings (l), (a), (b), (e) and (l).

To fix this, simply change the quoted code above with the proper (label), or change your labels to single characters.

Answer 2

You may also like to try MathPSFrag, which I've had lots of success with in the past.

It automatically creates (customisable) psfrag labels for every string in the image.