I go through the logic: It go through all osmways, and count the occurrence of nodeID. if nodeID appear only once, it's a pillar node. otherwise, it's a tower node.
That's it. Do I miss something? *Best Regards,* *ZhiQiang ZHAO* On Wed, Jun 3, 2015 at 11:55 AM, Peter <[email protected]> wrote: > Hi, > > there is no separate merging logic (although there was in 0.1 or > something). In OSMReader it is decided when an edge is created and e.g. OSM > ways are splitted if there are barriers or junctions on the way. So it > decides whether an osm nodes will be a tower node or just a pillar node > > Regards, > Peter > > > On 03.06.2015 20:35, John Zhao wrote: > > Hi Peter, > > Could you tell me where is the merging logic? > That's interesting. > > *Best Regards,* > *ZhiQiang ZHAO* > > On Wed, Jun 3, 2015 at 12:09 AM, Peter <[email protected]> wrote: > >> Hi Jan, >> >> we do this kind of 'merging' logic already in the import step when >> deciding what should be handled as tower node and what is a pillar node. >> Otherwise you'll need as twice as many RAM when copying from one graph to >> the other. >> >> >> > Have you made a experiment to count the number of 2 degree nodes with >> the equal flags and name in OSM? >> > And then we can know how many edges we can save. >> >> Yes, this should be done before implementing it :) >> >> And as the merging logic is currently not 100% optimal, there could be >> some minor savings even when recognizing the different street names, but >> I'm unsure if it is worth the effort. >> >> Issues like #234 or #111 will probably make more difference. >> >> Kind Regards, >> Peter >> >> >> On 02.06.2015 22:35, John Zhao wrote: >> >> Hi, >> >> AFAIK, there is no this kind of merging logic here. >> Wait the answer from Peter. >> Probably you need to implement it by your own. >> And it's not easy. >> Maybe can be done before import? >> What you want, is actually convert a tower node to a pillar node. >> >> >> *Best Regards,* >> *ZhiQiang ZHAO* >> >> On Tue, Jun 2, 2015 at 1:27 PM, Jan Torben Heuer <[email protected]> wrote: >> >>> Hi ZhiQiang ZHAO, >>> >>> Thanks for your quick answer. >>> I have a custom FlagEncoder that imports only very few ways and I don’t >>> need the names. I guess, I have mostly nodes with a degree of two. >>> >>> Jan >>> >>> Am 02.06.2015 um 21:53 schrieb John Zhao <[email protected]>: >>> >>> Hi, >>> >>> Have you made a experiment to count the number of 2 degree nodes with >>> the equal flags and name in OSM? >>> And then we can know how many edges we can save. >>> >>> I doubt this should be not too much for OSM. >>> >>> *Best Regards,* >>> *ZhiQiang ZHAO* >>> >>> On Tue, Jun 2, 2015 at 11:59 AM, Jan Torben Heuer <[email protected]> wrote: >>> >>>> Hi, >>>> >>>> Can Graphhopper merge two ways with equal flags and name if there is no >>>> intersection between them (no third way connected)? >>>> >>>> I would like to create a very reduces graph with only few edges. What >>>> would be the easiest way to achieve it? I think I would have to disable the >>>> nameIndex for instance. >>>> >>>> Thanks, >>>> >>>> Jan >>>> >>>> >> > > _______________________________________________ > GraphHopper mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/graphhopper > >
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