[OSM-talk] Ideas for student project on OSM

[paul youlten]

I´d like the OSM equivalent the "watchlist" function in MediaWiki.
Ideally I would be able to get an email alerting me when changes are
made to areas I am interested in.


On Tue, Oct 28, 2008 at 11:35 PM, Matt Amos <zerebubuth at gmail.com> wrote:
> On Tue, Oct 28, 2008 at 8:24 PM, Freek <freek_osm at vanwal.nl> wrote:
>> I have not seen those (would be interested), but I would guess rectangular
>> queries make an equilateral-triangle subdivision inherently less favourable,
>> even though the geometry is distorted by the projection
>
> i think it might have been this one... or maybe not... it was a long
> time ago :-)
>
> http://research.microsoft.com/research/pubs/view.aspx?tr_id=736
>
>> (we don't have much
>> data near the poles anyway ;-)
>
> this is exactly why an icosahedral decomposition is so good - each
> tile in the same level of the tree is very nearly the same projected
> area. the quadtile approach (whether using 3395 or 4326) projects to
> much smaller areas near the poles than the equator, so wastes valuable
> coordinate space and unbalances the tree. if the icosahedron is
> oriented correctly (fuller's dymaxion orientation) then several of the
> triangular faces are completely filled with ocean and can be omitted.
>
> cheers,
>
> matt
>
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