Pete, the iPhone Tracker application is showing data points in a grid-like pattern, with multiple points visible simultaneously.
I haven't dug into the raw data - is that an artifact of the iPhone Tracker application, or is the raw data already rounded by Apple to fit on a grid, with multiple locations having identical timestamps?
How much I care about this depends a lot on the granularity of the underlying data.
To make it less useful for snoops, the spatial and temporal accuracy of the data has been artificially reduced. You can only animate week-by-week even though the data is timed to the second, and if you zoom in you’ll see the points are constrained to a grid, so your exact location is not revealed. The underlying database has no such constraints, unfortunately.
I just went through the code and it is indeed pretty trivial to remove both restrictions. If you want to do it, in the iPhoneTrackingAppDelegate implementation file:
* Change the precision variable on line 149 to something bigger than 100 (10000 did it for me) - this will mark points in the map with higher precision:
const float precision = 10000;
* Change the timeBucket variable on line 180 to change the date precision (the app currently gives you weekly based data, but it can go as far a data point every second). You could also just "cheat" and change the notion of weekInSeconds:
Yo! I realise the likelihood of you seeing this is very low, but is there any chance you would do a brief runthrough of how to implement this code? I'm very interested to increase the precision of this app but don't know enough and can't locate the iphonetrackingappdelegate file you speak of..
Thanks for posting the instructions. After doing this, it's easy to see that the tracking data is way off base quite a lot. And interestingly, places I visit a lot but never use my location for it has very few data points for. In fact, there's only one even near my office, which I visit nearly 5 days a week. Every week.
I haven't dug into the raw data - is that an artifact of the iPhone Tracker application, or is the raw data already rounded by Apple to fit on a grid, with multiple locations having identical timestamps?
How much I care about this depends a lot on the granularity of the underlying data.