Showing (un)connectivity while graph building (or as a report)

[Stefan de Konink]

A few days ago the situation with Station Voorschoten came up. Four
platforms that behaved as islands within the graph. Since it is extremely
uncommon to have such islands I wonder if we could automatically highlight
those as feature of analyst or just as report, including urls to
OpenStreetMap, for example, to address the issue.

What do people think about this?

Stefan

[Andrew Byrd]

On 05/15/2013 07:13 PM, Stefan de Konink wrote:
> A few days ago the situation with Station Voorschoten came up. Four
> platforms that behaved as islands within the graph. Since it is
> extremely uncommon to have such islands I wonder if we could
> automatically highlight those as feature of analyst or just as report,
> including urls to OpenStreetMap, for example, to address the issue.

Has anyone verified that this problem was indeed being caused by islands
in the graph? That seems very likely since the problem occurs on otp.nl
but not on GoAbout's graphs.

Islands are indeed extremely common in OSM, and for that reason we have
the PruneFloatingIslands graph builder module. I run it in every graph
build, and recommend doing the same -- it will save you a lot of pain.
It will output a log entry / graph annotation for each island removed,
including a representative vertex.

-Andrew

[Thomas Koch]

Could be the case if OSM files are different, otp.nl is last updated on 8 May.

Contribution ben-moovit patched the prunefloatingislands module to have it export a table including geometries of floating islands, would be easy to render this with Mapnik or whatever preferred geo solution.

Kind regards,

Thomas Koch

Op woensdag 15 mei 2013 19:24:53 UTC+2 schreef Andrew Byrd het volgende: