[GraphHopper] There must be bug on the subnetwork removal

[Peter]

Hi ZhiQiang,

yes, according to the wiki this is wrongly mapped:
/Avoid tagging highway intersections as that does not make clear which
way has the impediment. /

http://wiki.openstreetmap.org/wiki/Tag:barrier%3Dgate

Peter

On 23.07.2015 23:16, John Zhao wrote:
> Hi Peter,
>
> Maybe the following one related
> with https://github.com/graphhopper/graphhopper/issues/388#issuecomment-88066385 
>
> I have a look at 37.32611992939085,-121.9961998312816.
> It seesm related with barrier=gate at intersection.
> http://www.openstreetmap.org/node/1126492194
>
> *Best Regards,*
> *ZhiQiang ZHAO*
>
> On Thu, Jul 23, 2015 at 2:11 PM, Peter <graphhopper at gmx.de
> <mailto:graphhopper at gmx.de>> wrote:
>
>
>     There are two types of subnetworks and the smaller ones seems to
>     be 'one-way subnetworks' which means they are eg. only reachable
>     as destination or start. But if you would start from a
>     destination-only subnetwork you'll get 'not found' for all points
>     outside of this network.
>
>     Regards,
>     Peter
>
>
>     On 23.07.2015 23:03, John Zhao wrote:
>>     Interesting, 
>>     when I increase minOnewayNetworkSize from 20 to 50, the following
>>     two disappeared.
>>     subnetwork start from: 37.32611992939085,-121.9961998312816 size: 24
>>     subnetwork start from: 37.78373608999855,-122.25065187925067 size: 34
>>
>>     *Best Regards,*
>>     *ZhiQiang ZHAO*
>>
>>     On Thu, Jul 23, 2015 at 1:55 PM, John Zhao <johnthu at gmail.com
>>     <mailto:johnthu at gmail.com>> wrote:
>>
>>         Hi,
>>
>>         I tried car flag encoder with following parameter on San
>>         Francisco bay area data from mapzen.
>>         https://s3.amazonaws.com/metro-extracts.mapzen.com/san-francisco-bay_california.osm.pbf
>>
>>         minNetworkSize=200
>>         minOnewayNetworkSize=20
>>
>>         I printed all the remaining subnetworks.
>>         edges: 591932, nodes 437420, there were 3496 subnetworks.
>>         removed them => 13121 less nodes. Remaining subnetworks:5
>>         The remaining subnetworks are:
>>         subnetwork start from: 37.32611992939085,-121.9961998312816
>>         size: 24
>>         subnetwork start from: 37.56018439442332,-122.30257814308803
>>         size: 436637
>>         subnetwork start from: 37.78373608999855,-122.25065187925067
>>         size: 34
>>         subnetwork start from: 38.180185962770565,-121.70631393878864
>>         size: 301
>>         subnetwork start from: 37.85717050411933,-122.07633641532816
>>         size: 424
>>
>>         I don't understand why there is still subnetwork less than
>>         200 nodes.
>>
>>         I have a look at 37.32611992939085,-121.9961998312816.
>>         It seesm related with barrier=gate at intersection.
>>         http://www.openstreetmap.org/node/1126492194
>>
>>         *Best Regards,*
>>         *ZhiQiang ZHAO*
>>
>>

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