Thursday, June 12, 2008

LaTeX generated figures: Using preview instead of pst-eps

I've been using the pst-eps package when I want to generate EPS versions of coded graphics (e.g., graphics produced with PSTricks or the standard picture environment). From the pst-eps description:
Pst-eps is a PSTricks (pstricks)-based package for exporting PSTricks images ‘on the fly’ to encapsulated PostScript (EPS) image files, which can then be read into a document in the usual way.
By wrapping lines in a TeXtoEPS environment, you setup LaTeX to produce an image of the enclosed content with a tight bounding box. It works well, but you must use dvips -E to generate your EPS files with the proper bounding box. If you want to then generate a PDF, you have to use something like epstopdf (possibly with the EPSCrop GhostScript option) to do it. Additionally, there's a lot of overhead within the actual TeX source. In other words, it's not quite easy to use.

A BETTER OPTION: Today, I discovered the preview package, which is described with:
The package is a free-standing part of the preview-latex bundle. The package provides the support preview-latex needs, when it chooses the matter it will preview. The output may reasonably be expected to have other uses, as in html translators, etc.
This package appears to be a much nicer solution. You can use standard latex or pdflatex to compile. If you need to use latex but still want EPS or PDF outputs, you can use dvips and ps2pdf without any special options. Otherwise, the introduced preview environment works very similar to the old TeXtoEPS environment, but it requires less work to use and seems to apply to a broader class of content.

Here's an example that should not require anything fancy to build. If you don't have the amsmath package (you should), you can omit it and get rid of the gather* environment:
\documentclass{article} 
\usepackage{amsmath} % for gather*
\usepackage[active, % Turns previewing on
tightpage, % Squeezes pages around previews
textmath, % Subjects textual math to a preview
displaymath, % Subjects math displays to preview
floats % Subjects floats to preview
]{preview}
% There is a ``graphics'' option too that subjects
% includegraphics to preview. If they are already in a
% float, the ``floats'' option is sufficient.
\begin{document}

This text will NOT get printed.

\begin{equation}
a = b
\end{equation}

The math following the colon gets printed: $x = 5$?

\begin{gather*}
c = d
\end{gather*}

More text not printed.

\begin{preview}
Page 2 is here (with tight border).
\end{preview}

You'll never see this text.

\begin{figure}
\fbox{\fbox{\fbox{A figure that is printed}}}
\end{figure}

\end{document}
If the active option of preview is commented out, the file builds as if preview didn't exist. However, with it turned on, only the sections in preview environments get printed, and they each get put on a separate page with tight borders. Options like displaymath, textmath, and floats cause those types of content to get automatically wrapped with a preview environment.

Related posts:

1 comment:

Anonymous said...

Thanks for sharing! The preview package documentation definitely lacks such a working example.