[mkgmap-dev] Please test branch NET-no-NOD

Sat Oct 19 11:40:26 BST 2019

Hi Gerd

Maybe yes, but a long unconnected road is no use for route generation
except to somewhere else near the same road, which doesn't need route
generation anyway. Trying to get to anywhere else will probably give a
"route calculation error"

It occurs to me that almost the examples I've found are small networks
of paths where motor-vehicle=no. These are often the ones that get
picked up as the closest for starting/ending a car journey (wrong in
itself) and then cause "route calculation error" because of the
isolation from the main network.

Could there be some options to control the cut-off based on number of
nodes, total length, and non-motor vehicle?

I realise this is getting complicated.

Ticker

On Fri, 2019-10-18 at 15:51 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> I think it would be better to measure the sum of road lengths instead
> of the number of nodes.
> In some areas you may have unconnected roads with many km length,
> e.g. in Canada or Australia.
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Gerd Petermann <gpetermann_muenchen at hotmail.com>
> Gesendet: Freitag, 18. Oktober 2019 17:02
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Please test branch NET-no-NOD
> 
> Hi Ticker,
> 
> okay, I am working on the part that removes those islands from NOD. I
> am developing it with the NET-no-NOD branch.
> With trunk you get higher counts as each end of an unconnected way is
> also a routing node.
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Freitag, 18. Oktober 2019 16:28
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Please test branch NET-no-NOD
> 
> Hi Gerd
> 
> That runs OK.
> 
> As before, I get lots of 2 node roads - often bridges over streams in
> open land, and quite a few (about 1/10 the number of the 2 noders)
> are
> 3 and 4 nodes - frequently paths between buildings in schools /
> campuses and short bits of path at either end of the bridges in open
> land.
> 
> I upped the test from 5 to 10 and got more of the same + networks of
> short paths on golf courses, walkways on piers (which should have
> been
> connected to something), paths in an enclosed quadrangle, etc, etc
> 
> All of these I would consider to be a hindrance to route
> calculations.
> 
> Having an option, defaulting to, say, 10, to stop these road-islands
> being added to NOD must be a good idea. Setting the value to 0 would
> give the current behaviour
> 
> Ticker
> 
> On Fri, 2019-10-18 at 12:35 +0000, Gerd Petermann wrote:
> > Hi Ticker,
> > 
> > here is the patch without recursive call.
> > 
> > Gerd
> > 
> > ________________________________________
> > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> > von Gerd Petermann <gpetermann_muenchen at hotmail.com>
> > Gesendet: Freitag, 18. Oktober 2019 12:46
> > An: Development list for mkgmap
> > Betreff: Re: [mkgmap-dev] Please test branch NET-no-NOD
> > 
> > Hi Ticker,
> > 
> > thanks for testing. I'll work on a patch without recursive calls.
> > 
> > Gerd
> > 
> > ________________________________________
> > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> > von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> > Gesendet: Freitag, 18. Oktober 2019 12:41
> > An: Development list for mkgmap
> > Betreff: Re: [mkgmap-dev] Please test branch NET-no-NOD
> > 
> > Hi Gerd
> > 
> > I've applied the patch to my 'current' version and tried running it
> > but
> > it gives:
> > 
> > java.lang.StackOverflowError
> >         at
> > uk.me.parabola.imgfmt.app.net.RouteNode.visitNet(RouteNode.java:938
> > )
> >         at
> > uk.me.parabola.imgfmt.app.net.RouteNode.visitNet(RouteNode.java:941
> > )
> > ...  1020 lines like this ...
> >         at
> > uk.me.parabola.imgfmt.app.net.RouteNode.visitNet(RouteNode.java:941
> > )
> >         at
> > uk.me.parabola.imgfmt.app.net.RouteNode.visitNet(RouteNode.java:941
> > )
> > Exiting - if you want to carry on regardless, use the --keep-going
> > option
> > 
> > My source had the patches "avoid-to-split-via-ways.patch" and
> > "only_with_via_ways.patch". I can remove these and try again if you
> > think there might be an interaction.
> > 
> > I don't think there is a need to try and check on islands of
> > different
> > access modes; the apparent behaviour of my device is that it finds
> > the
> > closest highway of any type to get into or out of the main road
> > network. ie, if here is a footpath closer to the destination that
> > any
> > motor-vehicle road, car route planning will direct me onto it.
> > 
> > Ticker
> > 
> > On Fri, 2019-10-18 at 09:25 +0000, Gerd Petermann wrote:
> > > Hi Ticker,
> > > 
> > > please check: attached is a simple patch that implements the
> > > calculation of routing islands.
> > > It just reports islands with less than 5 routing nodes and the
> > > position of one of the nodes.
> > > It ignores such islands which have at least one node that is a
> > > boundary node.
> > > Remember that we also create nodes oncountry borders. Maybe those
> > > should be ignored here?
> > > 
> > > A more detailed test might also check the access attributes, so
> > > that
> > > we report islands for pedestrian, bicycle etc.
> > > 
> > > The patch doesn't change the data written to the img files.
> > > Please
> > > play with it and let me know how it works for you.
> > > 
> > > Gerd
> > > 
> > > ________________________________________
> > > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im
> > > Auftrag
> > > von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> > > Gesendet: Samstag, 12. Oktober 2019 19:34
> > > An: Development list for mkgmap
> > > Betreff: Re: [mkgmap-dev] Please test branch NET-no-NOD
> > > 
> > > Hi Gerd
> > > 
> > > I was thinking of a threshold (maybe < 5) and then not adding any
> > > of
> > > them to NOD.
> > > 
> > > The reason is that a while ago I found many instances where
> > > tracks
> > > lead
> > > up to the edge of car-parks but didn't join to each other or the
> > > car
> > > -park access road and so walking routing, where one was expected
> > > to
> > > cross the car-park, didn't work. I tried adding a footway around
> > > the
> > > edge of the car-park and this helped in a lot of cases but I got
> > > driving route-calculation-error in or out of the car-park if the
> > > access
> > > road wasn't correctly specified. Your latest change will help in
> > > a
> > > lot
> > > of instances but sometimes there car-park was defined by more
> > > than
> > > 1
> > > line.
> > > 
> > > Ticker
> > > 
> > > 
> > > On Sat, 2019-10-12 at 10:10 -0700, Gerd Petermann wrote:
> > > > Ticker Berkin wrote
> > > > > Do you attempt to isolate small road networks that are not
> > > > > connected to
> > > > > the rest of the system or just a single road?
> > > > 
> > > > Not yet. Do you think about some kind of threshold value giving
> > > > the
> > > > minimal
> > > > number of connections or maybe a bbox size or a sum of road
> > > > lengths?
> > > > if the
> > > > isolated network is "small" we might not add any of its roads
> > > > to
> > > > NOD.
> > > > Is that what you think about?
> > > > 
> > > > Gerd
> > > > 
> > > > 
> > > > 
> > > > --
> > > > Sent from:
> > > > http://gis.19327.n8.nabble.com/Mkgmap-Development-f5324443.html
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