Hi Andrzej,

I tried using --boundary-tags=administrative
for splitter, the amount of additional data depends
on the size of the largest boundaries.

Attached is a small patch that changes splitter so
that it keeps administrative boundaries complete
when the admin_level is between 5 and 11 (including).

This doesn't add much data to the output files
in comparison to --boundary-tags=administrative
when splitting e.g. Brazil with --max-nodes=800000
and --output=o5m:
a) r422 output size: ~ 359 M
b) patched version : ~381 M
c) unpatched r422 with --boundary-tags=administrative: 402 M

I've also tested the effect on mkgmap.
As expected, version a) produces some wrong / duplicate POI,
but I don't see them for b) or c).
The throughput is nearly identical, and the final img size is also almost equal.

So, I think the patch is the best compromise.

Gerd

> Date: Thu, 21 May 2015 12:56:43 +0200
> From: popej@poczta.onet.pl
> To: mkgmap-dev@lists.mkgmap.org.uk
> Subject: Re: [mkgmap-dev] Duplicate cities
>
> Hi Gerd,
>
> > Hmm, splitter keeps most mp-relations complete, we only
> > exclude some boundary relations.
>
> I see. But maybe potential increase wouldn't be that big, if you add
> boundaries?
>
> Or maybe you can preserve only some levels of boundaries?
>
> Or you can use boundary data form --bounds option?
>
> Anyway, I prefer version 1 - keep complete relation, that could be
> useful for mkgmap.
>
> --
> Best regards,
> Andrzej
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