相关步行分析PHP - 算法PHP

I'm currently building a PHP based social media crime analysis website for a university project. I'm very keen on including the 'correlated walk analysis' technique into my website.

This technique is detailed here on page 14: http://www.icpsr.umich.edu/CrimeStat/files/CrimeStatChapter.9.pdf

It specifies this algorithm: (E(d) = drms * sqrt N) I can't post images so here's the link to the image:

I was wondering what the best way/technique is to get this into PHP - if it is at all possible? I have access to my own server.

I have grabbed a large amount of location data from social media, so assume I have enough data to complete the algorithm.