For the last example we will use some real-world data and create a simple version of a commonly used application.
The dataset is taken from a cyclist racing a 10 mile time trial. Every two seconds his bike computer records a GPS location, and the racer's heart rate. It records current speed in meters per second based upon elapsed time and GPS fix. The recorded data is provided as an XML file containing a series of trackpoints:
<Trackpoint> <Time>2010-08-03T18:11:35.000Z</Time> <Position> <LatitudeDegrees>53.060790784657</LatitudeDegrees> <LongitudeDegrees>-1.0703133791685104</LongitudeDegrees> </Position> <AltitudeMeters>66.4000015258789</AltitudeMeters> <DistanceMeters>4.050000190734863</DistanceMeters> <HeartRateBpm> <Value>89</Value> </HeartRateBpm> <Extensions> <TPX> <Speed>4.057000160217285</Speed> </TPX> </Extensions> </Trackpoint...