Javadoc and MathJax


Tuesday, 29 January 2013

I recently found it necessary to add math to javadoc comments; MathJax makes this super easy!

Simply include the script using javadoc’s header argument.

javadoc -header "<script type='text/javascript' src='http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML'></script>" [YOUR_PACKAGE_HERE]

Adding this to a build process requires considerable escaping. Thanks to this post for the tip. I’ve included an example for Ant.

<javadoc additionalparam="-header &apos;&lt;script type=&quot;text/javascript&quot; src=&quot;http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML&quot;&gt;&lt;/script&gt;&apos;">

Now you can use the LaTeX math delimeters, \(...\) and \[...\], in your javadoc comments! Here’s an example…

/**
 * Laplaician smoothing.
 * @return \( \displaystyle \bar{x}_{i}= \frac{1}{N} \sum_{j=1}^{N}x_j \)<br />
 * Where \( N \) is the number of adjacent vertices to node \( i \) and \( \bar{x}_i \) is the new position for node \( x_i \).
 */
public PVector laplacianSmoothing() { ...

The math in this comment will be formatted as:

\[\bar{x}_{i}= \frac{1}{N} \sum_{j=1}^{N}x_j\] Where \( N \) is the number of adjacent vertices to node \( i \) and \( \bar{x}_i \) is the new position for node \( x_i \).

On a side note, the LaTeX for the equation above was lifted directly from the Wikipedia page on Laplacian Smoothing. I found it in the alt attribute of the img tag (the equations are stored as PNGs). A nice little time-saver!

Next step: getting this to work with TeXDoclet