Hi WanMil, On Tue, Jan 19, 2010 at 07:04:54PM +0100, WanMil wrote:

...

This seems to be another bogus warning:

2010/01/19 09:26:47 WARNING (MultiPolygonRelation): Cannot join the following ways to closed polygons. MP-Relation http://www.openstreetmap.org/browse/relation/302408

I did josm 'http://www.openstreetmap.org/?lat=64.73925&lon=29.49075&zoom=18' selected the relation of the node and downloaded all members in the relation editor. Each 'inner' member (island) consists of a closed way according to the relation editor. (It shows closed loops next to the members.) The 'outer' member (coastline) consists of 7 ways, which form a closed loop. 6 of the ways are 500 nodes and the last one is 218 nodes.

To me, the data seems fine.

Marko

Marko,

there are some problems with mp code and osmosis/tile splitter. In your case I think it's the tile splitter.

In that run, I had split finland.osm.bz2 into three tiles, at two latitudes: lat=62.578125 and lat=64.819336. Later, to get rid of a data structure overflow in the southern tile, I moved the southern boundary to lat=62.226562. You can get my files at http://www.polkupyoraily.net/osm/.

The splitter puts only parts of the ways that crosses the tile bounds to the resulting tile file. The handling for these incomplete mp ways on the tile border is on the list which must be implemented next.

That is a plausible explanation. The lake runs from lat=64.6895 to lat=64.8580, crossing my northern tile boundary of lat=64.819336.

By the way: did you see that lake with the old mp code and the same splitter bounds?

There are many missing lakes in Northern Finland, even large reservoirs that are shown on Garmin's base map. I have not paid much attention to lakes before. Many lakes are displayed just as coastlines, but I hope that I can soon enable sea polygons. Finland's thousands of lakes and islands should be the ultimate "acid test" for multipolygon handling. Best regards, Marko