In a deviation from the scheduled program I am looking at displaying GPS data on a map - and it is a nice example of how assumptions (like “the data are complete”) can get you into trouble. You really need to have a close look at and know your data, and might even have to analyse them every time before processing them to be on the safe side. How big a problem are incomplete data? And how to deal with them? Read the article to find out … 
A shout out to Kem who’s very highly rated RegExRX app has again proved invaluable - I really consider it an essential tool every time I touch RegEx …
