Keynote does mathematics

Apple's Keynote presentation software makes it easy to create great looking presentations with professional themes, transitions, and charts and tables. If you need mathematics, though, you're out of luck. For some reason, Apple's designers failed to include anything more than the most basic tools for creating mathematical expressions, leaving mathematicians and scientists with little incentive to switch to Keynote.

The LaTeX Equation Editor provides an elegant graphical interface to LaTeX, a powerful typesetting engine for mathematics, enabling you to quickly generate professional-looking mathematics for inclusion in your slides. All equations are produced as single-page PDF files, so they can be smoothly resized and rotated like any other graphic object in Keynote.

All of Keynote's graphic operations can be applied to PDF files just as easily as bitmapped files. This includes rotation, constructing mirror-images, and applying shadows. Since the PDF files produced by the LaTeX equation editor are transparent except for the actual text, shadows applied to PDF equations only have the mathematical expressions casting shadows. Here's an example (click to enlarge):

Typesetting mathematics.

If you are already familiar with LaTeX, creating an equation is straightforward: You type in a description of the mathematical expression in the main text window, press the "LaTeX" button, wait a few seconds while the LaTeX engine works in the background, and then (assuming you didn't make any mistakes) the typeset equation appears in the graphic display. You can then drag-and-drop the equation into Keynote.

The Library
Previously typeset equations can be saved in equation libraries, so that you can reload entire batches of equations from presentations and make minor modifications without having to retype the entire equation.

The preamble
For those who know how to use LaTeX, the Equation Editor lets you customize the preamble used when typesetting the equation. The preamble is saved automatically whenever you quit the program, so all of your definitions, macros, and customizations persist from session to session.

Exporting equations

Equations can be exported to PDF files by choosing the "Export..." option beneath the file menu. You can also drag-and-drop the equation to the desktop, a folder, or any application that can accept a PDF file as input. (If you want bitmaps, there is a preference setting to make all equations exported via dragging TIFFs.) Normally this isn't necessary, since Keynote saves a copy of the equation as a PDF file whenever you paste one into a presentation. But the feature is there in case you want it.

One advantage of exporting your equations, though, is that they can later be read back into the Equation Editor. A copy of the LaTeX source code is saved inside the PDF file so that it can be extracted later. To open an equation from a saved file, either choose the PDF file from the "Open..." menu or drag it onto the main graphic display window.

How do I get it?

You can download the editor below. In order for it to work, you first need to have a working LaTeX distribution. A well-known, and widely used, distribution for Mac OS X is maintained by Gerben Wierda and can be downloaded from www.rna.nl/tex.html.

Once you have a working distribution of TeX and ghostscript, download the following:

LaTeX Equation Editor (Version 1.3) (~1.5 MB)

If you intend to use the program in a Japanese language environment, it won't work without a little tweaking.

After downloading, you should start the application and make sure that it knows where your LaTeX and ghostscript binaries are stored. Open up the Preferences pane and verify that these paths are correct. Once they are, you're ready to go!

If you want the source code (it's kind of ugly), you can download it here.

Version history

Version 1.3

Fixed a number of bugs, added save capability to the equation library, reworked the interface so that the main graphic image window was resizable, added an "adjust bounding box" tool, and many other things.

Version 1.1.1

Added two options to the Preference pane:
1. Style of main image well frame. (If you modify the application to make it non-metalicized, you might find the produced equation difficult to read. This option lets you change the image well to one of five different formats, one of which might help increase the visibility of the equation.)
2. Recompute bounding box before distilling. (Although dvips often produces EPS files with accurate bounding boxes, occasionally it is wrong. This occurs most frequently when the EPS file contains graphical output from PStricks or other programs. This option recalculates the bounding box to insure that the bounds of the PDF file are accurate. This option additionally lowers the bounding box by two points to adjust for the clipping error that occurs when displaying some PDF files in the main image well.)

Version 1.1

Fixes to all bugs reported thus far. (The "You MUST view the error log!" bug, in particular.)
Typeset equations stored inside a unique subdirectory of /tmp rather than the bundle.
Preamble and paths stored as normal user preferences.
Some GUI polishing (attaching a text formatter to the Pt. size. text box so that no non-numbers can be entered), removing bogus menu choices.
Some documentation enhancements.
Removed the "thick" client as a download option.

Version 1.0.1

Introduced the "thin" client.

Version 1.0

Original release of the "thick" client, which generally didn't work, thus producing much chagrin and wasting of download time. Sorry.

J. McKenzie Alexander
Department of Philosophy, Logic and Scientific Method
London School of Economics and Political Science
Houghton Street, London WC2A 2AE