Custom Formatters

I'm putting together a personal site to keep track of local trails; I want to render a map from an uploaded GPX file, no problem so far using FileField, Geocoder and Leaflet. To make it a bit more interesting I would like to add a little more information such as a table or list with Distance, Vertical Climb, Vertical Drop, Grade (average), Grade (max), Altitude (min), Altitude (max) and a chart plotting vertical over distance.