[GraphHopper] What are pillar and tower Nodes? Rename to geometry and junction nodes?

[Peter]

Hi together,

I've thought now long about this (maybe too long ;)) and I'll leave it
as it is. The problem with "geometry"-node is that it refers to
edgeState.fetchWayGeometry and we can get tower node geometry from this
method too which might be confusing. The problem with "junction"-node is
that end-standing nodes (in blind alleys) are no junctions.

And so, I've just updated the documentation here:
https://github.com/graphhopper/graphhopper/blob/master/docs/core/low-level-api.md

Regards,
Peter

On 02.12.2014 09:20, Peter wrote:
> Thank you all for your input!
>
>
> > in GI science we speak of 'vertices' for pillars and just 'nodes' or
> 'junctions' for that what you know as tower nodes.
>
> Vertices vs. nodes is not a choice as one uses 'nodes' in graph theory
> but also sometimes 'vertices'. Also I use them as synonym :)
>
> Are there other alternatives?
>
>
> > Without looking at the documentation, I wouldn't know what
> "junction" and "geometry" nodes are either.
>
> Yeah, probably :)
>
>
> > Yes definitely!
>
> > I'd say that junction and geometry is more immediately descriptive
> and intuitive,
> > though the meaning of tower/pillar isn't really obscure. It would
> seem a small but worthwhile improvement in comprehension/usability
>
> Okay, so I'll do the change (after waiting a week for vetos or other
> suggestions) and properly document this stuff in the low level API:
> https://github.com/graphhopper/graphhopper/blob/master/docs/core/low-level-api.md
> and reference to this e.g. in the OSMReader etc
>
> Regards,
> Peter
>
> On 01.12.2014 20:44, Jürgen Zornig wrote:
>>
>> Well, in GI science we speak of 'vertices' for pillars and just
>> 'nodes' or 'junctions' for that what you know as tower nodes. Coming
>> from GI I found it hard to understand what towers and pillars should
>> be until I read some documentation about it. So by talking about
>> vertices at least, it would get much clearer for.a whole bunch of
>> geomatic related people.
>>
>> Am 01.12.2014 19:38 schrieb "D KING" <david.king.bath at btinternet.com
>> <mailto:david.king.bath at btinternet.com>>:
>>
>>     I'd say that junction and geometry is more immediately
>>     descriptive and intuitive, though the meaning of tower/pillar
>>     isn't really obscure. It would seem a small but worthwhile
>>     improvement in comprehension/usability.
>>
>>
>>
>>         ------------------------------------------------------------------------
>>         *From:* Peter <graphhopper at gmx.de <mailto:graphhopper at gmx.de>>
>>         *To:* graphhopper at openstreetmap.org
>>         <mailto:graphhopper at openstreetmap.org>
>>         *Sent:* Monday, 1 December 2014, 16:01
>>         *Subject:* [GraphHopper] What are pillar and tower Nodes?
>>         Rename to geometry and junction nodes?
>>
>>         Hi all,
>>
>>         as the naming is from 2 years ago I think it could be time to
>>         rename
>>         'tower' nodes into 'junction' nodes and 'pillar' nodes into
>>         'geometry'
>>         nodes. What do you think, would this be (more) intuitive?
>>
>>         Below a quick documentation which I would add otherwise to
>>         the docs.
>>
>>         Kind Regards,
>>         Peter
>>
>>         **
>>         From OpenStreetMap we fetch all nodes and create the routing
>>         graph but
>>         only a minority of them are actual junctions, which are the
>>         ones we are
>>         interested while routing. Those junction nodes I call tower
>>         nodes which
>>         also have a graphhopper node ID associated, going from 0 to
>>         graph.getNodes(). The helper nodes between the junctions I
>>         call 'pillar
>>         nodes' which can be fetched via
>>         edgeIteratorState.fetchWayGeometry
>>

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