Making gorgeous LaTeX plots with Octave

I previously wrote about using the epslatex terminal in Gnuplot to generate beautiful plots for inclusion in a LaTeX document. The secret is that the epslatex terminal produces a combination of (1) EPS vector graphics and (2) TeX instructions to overlay all the text (axis labels, legends, etc.) in whatever font you are using in the rest of your document. So typically you get that super slick looking Computer Modern Roman (cmr) font.

Now, there are some things that are beyond the ken of Gnuplot. So it was a relief when I learned that GNU Octave can produce similarly formatted EPS + TeX graphics. What's nice about using Octave instead of Gnuplot is that, not only can you take advantage of Octave's more advanced (as I understand it) graphics facilities, but you can also bring to bear all the power of a full mathematical/simulation language for preprocessing your data or whatnot. I still usually use Gnuplot, but I break out Octave for making plots when necessary.

All you have to do is produce your plot in Octave as normal (e.g. plot(...)), and use a command like the following to output in EPS + Tex:

print('my_plot.tex', '-dtex');

As an example, here's some minimal code to produce a heatmap with contours and a legend:

x_values = [0.10 : 0.005 : 0.60];
y_values = [0.10 : 0.005 : 0.60];
contourf(x_values, y_values, data); % supply your own data...
axis square;
colorbar;
xlim([0.1 0.6]);
ylim([0.1 0.6]);
print('-dtex', 'my_plot.tex');

Octave really saves the day here. To the best of my knowledge it is difficult or impossible to do this using just plain Gnuplot, especially if you are not plotting over a square area.

Using itsalltext with emacs/emacsclient

I finally started using It's All Text!— this is something I should done long ago. (It's All Text! is a Firefox extension that lets you invoke an external editor to edit the contents of any textarea element, like this blog post I'm writing right now in Blogger.)

There's such a stark contrast between using Emacs, where I feel at one with the document, and typing in the browser textarea, which always makes me feel kind of claustrophobic now (the problem is not that the textbox is too small, but that it doesn't provide enough degrees of freedom for editing).

If you are using an Emacs with multi-TTY support (a v23 snapshot), you can leave one long-lived Emacs server instance running and quickly pop up a new frame from it for each editing buffer:

1. From your main Emacs frame, run M-x server-start.
2. Save the following wrapper script (I called mine ecw) and configure it to be your editor in It's All Text!:

   #!/bin/sh
   /usr/bin/emacsclient -c $@

3. In the It's All Text! options you can configure your favorite hotkey to launch a new Emacs frame for editing.
4. When you're done with a buffer, save and press C-x # to return to Firefox.

Update: another tip. To automatically fire up html-mode when editing text from, say, blogger.com, you can add something like this to your .emacs:

(add-to-list 'auto-mode-alist '("/www\\.blogger\\.com\\.[^/]+\\.txt\\'" . html-mode))

This works because the temp file that It's All Text! creates has a name like www.blogger.com.2a2q1e2r32.txt.