Well, thus the conclusion of this thread is that there is no way to make some kind of universal routing database ?
It would be disapointing, but I can accept that and stick with my home-made parser. However, about the metrics, I was thinking of keeping the nodes describing the geometry (thus redundancy with the Ways). The information has to be in the database to use the metrics you want. But it's not okay to have to do some fancy parsing/splitting just in order to get a stupid G(N,A) graph. Most likely it's pointless to argue about how to do it, there won't be any agreement how to do things. It's a pitty the OSM API is bogous and was only thought about graphical rendering. Having some basic routing information is a hassle of exception, particular cases and so on... On Mon, Oct 20, 2008 at 5:58 AM, Marcus Wolschon <[EMAIL PROTECTED]>wrote: > On Mon, 20 Oct 2008 05:28:02 -0700, "Tristram Gräbener" > <[EMAIL PROTECTED]> wrote: > > Hello, > > > > After some thoughts, I think that what I would need, is only the > > current xml files, where there is a constraint that each way may be > > only made of nodes of degree 2 (except at start and end). Of course I > > guess that there is no way to change the API ;) > > > > Wouldn't be it easy to make that as the exchange format, e.g. by > > adding a Link property made of nodes ? Of course this would break the > > normal form as it would be redundant to ways. > > I think the issue is a bit more complicated then this. > * Not all ways are roads. You can have nodes that are of a > degree > 2 only because they are also used by a passing > river or similar. > * Before reducing roads to links between intersections you need > to compute your metrics. You loose all information about the > length and path of the road. > * This really means _your_ metrics. Others may want to add a penalty > for curvy mountian-roads in addition to their length+highway-class > or they may compute for a truck instead of a sports-car. > > Thus you can do some routing on a graph reduced as proposed > by you but you will not be able to compute the shortest, nor > the fastest route as you will have lost that information in > the export. > > > A universal binary format with some API would be nice for people that > > want to play with graph algorithms (like students) but I personnaly > > have no use for that (yet). > > Well, you don't have to. > I have no need for many other features, so > I let them be and don't care about them. > > > > _______________________________________________ > Routing mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/routing >
_______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/listinfo/routing
