[OSM-talk] Some question about OSM

[Andy Robinson]

Nicola Ranaldo wrote:
>Sent: 30 June 2006 09:52
>To: talk at openstreetmap.org
>Subject: [OSM-talk] Some question about OSM
>

Welcome Niko,


>I'm writing a qt4-based OSM client in order to render maps and doing route
>planning with speech instructions (festival). It has some basic editing
>capabilities too.  Depending on my free time, when the code will be cleaned
>and optimized, i'll release it under gpl.
>While approaching i collected some technical questions for you:
>
>*) wiki says a segment could belong to several ways, is there a specific
>reason for that?

Yes, a segment can belong to any number of ways as the way feature is
intended for use not only as part of a physical route but also for other
associations. For example, a segment might be part of the following ways:
A street
A bus route
A walking tour route
A cycle race
etc etc...

>
>*) osmplanet data seems to contains some dirty informations, tests,
>orphaned
>objects and so on... is it normal?

A small amount of bad data from testing in the early stages exists but is
pretty small as far as I know. There are also editing errors where key names
have been poorly entered. These get corrected with time plus at some point
they might be corrected automatically (probably by client software) for some
well used keys.


>
>*) wath's the best approach to do street and place names rendering?
>disposition of text will be evaluated by software in real-time? will be
>some
>key/value helping rendering software ? (for example, a tag could say render
>this town names at x,y, or <important> do not render it when scale > z and
>so
>on)
>

I'll leave that to others to comment upon.

>*) my route planning code actually works on every raw segment/node, is this
>right? should it run only on "junction" nodes? should the software use the
>first option and take help from the second when available? this questions
>due
>to lack of junctions tagging in data , i think routeplanning helpers should
>be strong formalized, in order to modify editors and avoid huge maps
>reediting
>

I'm not working on navigation but from my editing experience and logic I
would say best to work with the segments if you can as there is no reference
to the associated segments with the node data. 


>*) do you think distibuting (with zone delegation ala DNS) database may be
>an
>idea (with rest api modifications) ?
>

I'll leave that to others to comment upon.

>*) a stupid question, some segments have k="highway" v="primary", and
>others
>k="class" v="primary"... is it normal?

Any key and value is possible and at the start the class=primary was the
primary method. However the highway=primary is widely used as I personally
have found it more flexible but the jury is out as to whether a better
format will emerge in the future. Remember, one of the features of OSM is
that there are no restrictions on what key and value pair can be used.

Personally I think anyone wanting to rely upon the map data for route
navigation should add their own keys and values as appropriate for this
purpose.

>
>Thank you
>
>	Niko
>
>_______________________________________________
>talk mailing list
>talk at openstreetmap.org
>http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk


Cheers,

Andy

Andy Robinson
Andy_J_Robinson at blueyonder.co.uk