On Sun, Jun 27, 2010 at 07:11:53PM -0500, Nolan Darilek wrote: > 2. As a blind pedestrian, I'm not likely to travel faster or slower on > streets of different types. Vehicular navigation of course is another > story, but in this instance, vehicular nav is secondary. Also, whether > or not a street is one-way is immaterial. Same with dead-ends. Do I have > anything to gain from examining way tags, or am I dismissing that avenue > too soon? It seems to me like my approach would need to be purely > mathematical in this case. I'm sure you should examine those tags. First not every line is a road, it could also describe (district) boundaries[1] or house numbers[2]. You might not be interested in those. Or you might not want to walk on motorways ... On the other hand you could get information suiting special needs of blind pedestrians: Whether there is a sidewalk on the left or the right side[3], if a pedestrian crossing has acoustic guidance, etc. Check out the page "OSM for the blind"[4].
> 3. In dusting off my disused (and never that good to begin with :) math > skills from over a decade in my past, I'm thinking that a vector-based > solution might work. I am already calculating a node's neighbors if it > is on one or more ways, so I think that if I create vectors between the > nearest node and each of its neighbors, then determine which segment has > the least distance to the user's current location, then I've figured out > the user's new way with minimal complexity. Before I go off and > implement this (or rather, before I figure out which vector operations > apply here and *then* implement this :) can anyone tell me why this may > be a bad idea? I think this is a very good idea :) Check out the "Hesse normal form"[5] how to calculate the distance of a point to a line. [1] http://wiki.openstreetmap.org/wiki/Key:boundary [2] http://wiki.openstreetmap.org/wiki/Karlsruhe_Schema [3] http://wiki.openstreetmap.org/wiki/Proposed_features/Advanced_footway_and_cycleway [4] http://wiki.openstreetmap.org/wiki/OSM_for_the_blind [5] http://en.wikipedia.org/wiki/Hesse_normal_form greetings, Stephan -- Seid unbequem, seid Sand, nicht Öl im Getriebe der Welt! - Günther Eich ,---------------------------------------------------------------------. | Stephan Plepelits, | | Technische Universität Wien - Studien Informatik & Raumplanung | | Projects: | | > openstreetbrowser.org > couchsurfing.org > tubasis.at > bl.mud.at | | Contact: | | > Mail: sk...@xover.mud.at > Blog: plepe.at > Jabber: sk...@fsinf.at| | > Twitter: twitter.com/plepe > Wave: plepel...@googlewave.com | `---------------------------------------------------------------------' _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev
