[talk-au] Victorian Coastline

4x4falcon info at 4x4falcon.com
Thu Jan 27 09:21:24 GMT 2011


On 27/01/11 14:12, Steve Bennett wrote:
> On Thu, Jan 27, 2011 at 3:10 PM, 4x4falcon<info at 4x4falcon.com>  wrote:
>> Physical things can change (eg road or railway realignment), non physical
>> don't necessarily change.  In the case of boundaries do we definitely know
>> that when a road is realigned does the boundary change with it.  This has
>> been discussed many times since the import of the ABS boundary data.
>
> My guess would be that the boundaries generally do change, but I could
> be totally wrong. And I think high quality traces are likely to be
> more accurate than the ABS's data.

That's the problem it's your guess.  There has been no definitive answer 
since the original import.

Yes I agree we need to improve the coastline mapping and the bing 
imagery allows us to do that significantly especially in remote areas. 
BUT don't guess find out for sure if the boundary firstly is meant to be 
the coastline and if the coastline or whatever changes does the boundary 
change.  It probably does but I don't know for sure either.

>> For editing (particularly for new users) it is easier to select which one to
>> edit (particularly in potlatch) and not try to select the correct one using
>> the appropriate keyboard shortcut which is not immediately apparent.
>
> Me, I think ease of editing should rate pretty low compared to quality
> of rendering or correctness. Incidentally, I have just checked in a
> new feature to Potlatch which will make it very easy to create
> colinear ways. Not sure when/if it will appear in the public version.

So your mapping for the renderer.

Have a look at this:

http://www.openstreetmap.org/?lat=-34.82843&lon=138.68718&zoom=16&layers=M

Does the boundary appear in the middle of the road on Montague Road.

Is it colinear or close nodes, without looking at in an editor?

If you look in an editor such as josm you will see that its two separate 
ways with the nodes on the boundary varying between 1 and 3 metres away 
from the road nodes.  You don't need to make the ways colinear for it to 
appear so on the rendered map.  If they are parallel with the nodes 
within a metre of each other then it will appear colinear on the map.

If they were put side by side ie like this =:= less than a metre apart 
there is no difference to rendering but you then have an easy means to 
select either way in any editor and the easier it is to add something, 
or modify something then more people will do so.

Need to move the ways because the coastline has changed, then select 
both nodes and drag them to the new position.

Cheers
Ross







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