Geospatial-Distance Calculators

When working on http://www.dssa.com.au!LINK BROKEN! I had to figure out how to find the nearest driving schools to the users location. To do this I needed to geocode their address (convert their address to Latitude and Longitude) and check it against my database of driving schools. My database contained the driving schools addresses already geocoded so it was then just a matter of comparing the two. I created a Geocodetestsuite that compares the performance of various ways I have used to calculate the distance.

NOTE 4.11.2016: previously the performance of option 3 took the longest however with the resurrection of my blog I see that the microtime for it is not comparable with option 1. I have not had the opportunity to review why this is.