[Tagging] natural=bay as nodes are evil

Ilpo Järvinen ilpo.jarvinen at helsinki.fi
Tue Oct 28 11:41:51 UTC 2014


On Tue, 28 Oct 2014, Christoph Hormann wrote:

> On Tuesday 28 October 2014, Janko Mihelić wrote:
> > > If you want to formulate a formal mathematical rule for where the
> > > node for a bay is best placed: Place it so the variance of the
> > > distance of the node to the bay's shores is minimized.  Most
> > > existing nodes comply with this rule remarkably well.
> >
> > What's the best place for the node in Guantanamo Bay? Is the current
> > node well placed?
> 
> I'd say it is.
> 
> Note the algorithm i sketched in its simple form would seriously 
> underestimate the bay size due to the peninsula in the middle - same 
> problem as small islands in the bay which i already mentioned.  It is 
> fairly easy though to detect and fix this (by making use of the fact 
> that a bay is 'mostly surrounded by land').

I see. This underestimation in the peninsula case was why I though you'd 
want the nodes at the entry point and thus my earlier comment about 
natural=bay_entry.

But are all bays 'mostly surrounded by land' or do some bays also have 
very wide entrypoints (in addition to two pockets to trigger this 
peninsula case)? And yes, I know it can always be solved by drawing area 
manually if the algorithm won't get it right.

Btw, instead of huge and fragile areas we could just create a relation 
which holds the coastline nodes of the bay extreme end points. Although 
also that would probably be just as fuzzy as the outer edge would be 
(i.e., where the bay really would end along the coastline).


-- 
 i.


More information about the Tagging mailing list