6 ms·
This is neat but the map by public transport time is probably non-euclidean because subways are like wormholes.
by adamcanady 2y ago
This is neat but the map by public transport time is probably non-euclidean because subways are like wormholes.
- ars 2y agoNot really - you have to wait for the subway, it also takes a finite time to travel, and it frequently stops. It can avoid traffic, but the actual MPH can be slower than a car when you include both those things.
- echoangle 2y agoIsn’t the point that you have a way to get to a point far away faster than you can get to a point in between? The worm hole thing ist because you can only exit at discrete points so it pulls a single point far away, and it’s sorrounding, closer to the starting point. That’s probably hard to map to a 2D map because there would be some overlap between the different „islands“ starting from subway stations
- episteme 2y agoIf you could take the shortest path to each point, it would solve the problem and be interesting. Not necessarily easy to do though.
- aaron695 2y ago[dead]
- perihelions 2y agoRight, the travel-time metric is not compatible with a Euclidean R² metric. You can imagine three subway stations in a triangle loop, such that it's a shorter trip to do a full loop on the subway then to walk to a point in the interior. There's no way to continuously deform a map so that it represents travel times as distance in a plane.
- vvolhejn 2y agoOh yes, unfortunately, you can't do this perfectly. There are some graphs that cannot be embedded in Euclidean space in any number of dimensions, e.g. a 4-cycle with distance measured by path length. It's a good-enough approximation for visualization purposes, though.