## 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 '<script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>'">
```

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…