[mkgmap-dev] tile size?

Fri Mar 20 14:04:18 GMT 2009

I am planning to do manual splitting only if necessary and use a simple 
divide by half scheme but with horizontal or vertical selection when 
doing so (and thus have only some influence on the position of the 
split). I am certainly not planning on manually dividing the whole world 
by hand.

Routing between tiles should "just work (tm)" imho so very careful 
tilesplitting should not be needed.

Mirroring the maps is ofcourse no problem but they update each week and 
bandwidth is not a problem (yet, at least). So I don't know how 
effective mirroring actually is.

Marko Mäkelä wrote:
> Hi Lambertus,
> 
> On Fri, Mar 20, 2009 at 09:12:01AM +0100, Lambertus wrote:
>> North and South America split fine with max-nodes set to 120000. Europe  
>> still gives a few errors with that setting though. See the results of a  
>> complete world splitted with the 120000 setting here:  
>> http://garmin.na1400.info/routable.html
>>
>> I plan to split the remaining failed tiles manually.
> 
> Are you planning to fine-tune the tile division by hand?  If so, I would
> suggest that you avoid splitting South Finland or North Estonia in the
> west-east direction.  Given that there could be some inter-tile routing
> issues (suboptimal routes chosen), it would be better to have a tile border
> on the Baltic sea between Finland and Estonia.
> 
> I don't care which tile the Åland islands are on; they are roughly
> halfway between Sweden and Finland anyway.  Although they belong to
> Finland, they are autonomous and tightly connected with Sweden.
> 
> For what it is worth, my Finnish Garmin map generated from finland.osm.bz2
> at http://www.polkupyoraily.net/osm/ uses this areas.list:
> 
> 63240001: 2768896,890880 to 2916352,1472512
> #       : 59.414063,19.116211 to 62.578125,31.596680
> 63240002: 2916352,890880 to 3020800,1472512
> #       : 62.578125,19.116211 to 64.819336,31.596680
> 63240003: 3020800,890880 to 3266560,1472512
> #       : 64.819336,19.116211 to 70.092773,31.596680
> 
> The reasoning is that most of the population is located in the south,
> and therefore the south must be a single tile.
> 
> Similarly for Estonia, most population should be in the mainland, near
> Tallinn.  You could put the Saaremaa and Hiiumaa islands on a separate
> tile without losing any routing functionality.
> 
> I hope that you consider this suggestion.  If it works out well, I'd
> like to set up a mirror to your map tiles instead of generating the
> tiles myself.  (I only have a 32-bit machine on a 1 Mb/s ADSL line.)
> 
> 	Marko
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