Hi, On Fri, May 03, 2019 at 01:24:49PM +0100, Andy Townsend wrote: > Seriously, hoever wrote that section of that wiki page > https://wiki.openstreetmap.org/w/index.php?title=Relation:route&action=history > must have done so out of their _desire_ that relations are kept ordered in > OSM, not out of any observation that they actually _are_ ordered.
I haven't edited the wiki page but I'm likely responsible that it appeared because of this post: https://www.openstreetmap.org/user/lonvia/diary/42262 Please note the statistics at the end of the post. I actually did bother to observe the state of affairs and I found that a majority of routes in fact _are_ already sorted. The numbers are from before waymarkedtrails stopped sorting routes, i.e. they are not distored by the fact that people wanted to see a clean elevation profile on the site. > In OSM you need to deal with the data as it is, not as you'd like it to be - > the nature of the project, where anyone can contribute, and they may not be > even aware of concepts that you care deeply about makes it fundamentally the > worst place to be an architecture astronaut (as per > https://www.joelonsoftware.com/2001/04/21/dont-let-architecture-astronauts-scare-you/ > etc.). This judgement is a bit unfair unless you have actually tried to sort routes. It's easy for the 2/3 or so routes that are strictly linear. For everything else, it's hard. It's essentially an optimisation problem. And no matter what you do, part of your algorithm involves guessing what the mapper might have wanted. That is the point where I argue that the mapping is flawed and might miss some information that the mapper actual has at their disposal. Here is an example of a route that is really hard to sort automaticaly but is perfectly usable when used in the order it appears in the relation: https://hiking.waymarkedtrails.org/#route?id=1115137 > That's not to say that we can't try and make contributions better, but the > way to do that is to modify the tools that people use to contribute to OSM > not to write wiki pages that no-one reads before they start editing. As everything in OSM, you don't need to read that wiki page and you have the freedom to sort your routes or not. If you don't want to bother, that's perfectly fine. An unsorted route is not wrong, it's only less precise. Maps can show it without issues including waymarkedtrails. It just can't give you some advanced features. One more point: Most editors are quite good at keeping route order these days (iD has looong ago been fixed). But even when they get it wrong (mostly due to complicated way splits or reversals) having routes sorted actually means that the damage is less severe because when you stitch the remaining parts together, the result is still very usable. Kind regards Sarah _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
