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#1 2012-10-08 14:04:50

Greenland map problem

Hi,

I am trying build map of Greenland. I downloaded planet.osm because there is no extract for this country on geofabrik.de
There is not too much data so it shouldn't be problem build this huge map.
But when I build a map I have only upper right corner of map and Iceland area (which also belong to this huge area).

Any idea what can be wrong? I am doing my extract this way:

osmosis --read-pbf file="planet-121003.osm.pbf" --bounding-box top=84.00 left=-74.00 bottom=58.00 right=-10.00 --write-pbf omitmetadata=true greenland.osm.pbf

I also tried donwnload same area from  http://garmin.openstreetmap.nl/ to check if there is some general problem, but this was fine.

Thanks for help

mira

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#2 2012-10-09 10:27:22

Re: Greenland map problem

Hi,

The problem was in splitter  ...  --max-nodes=1600000 changed to --max-nodes=900000 solved problem
When I split with --max-nodes=1600000 then some "partial" img files had 0kB size when I builded map.
Interesting is that --max-nodes=1600000 was my usual setting before and I didn't got this problem.

regards

mira

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#3 2012-10-10 00:49:51

Re: Greenland map problem

Hmm..
I still have "empty" south/west corner of my map.
There is not area in which I am interested, but anyway I am very curious what is wrong with my work-flow. 

$ osmosis --read-pbf file="planet-121003.osm.pbf" --bounding-box top=84.00 left=-74.00 bottom=58.00 right=-10.00 --write-pbf omitmetadata=true greenland.osm.pbf

$ java -Xmx3072m -jar splitter-r200/splitter.jar --max-nodes=900000 --no-trim --description=Greenland --mapid=63240001 --overlap=10000 --output=pbf --output-dir=LAND greenland.osm.pbf

$ java -ea -Xmx6144m -jar mkgmap-r2337/mkgmap.jar test18.TYP --precomp-sea=/media/MEGA/MAPING/sea/ --style-file=my-style/ -c my-style/arguments LAND/6324*.osm.pbf

Splitter yielding six files ... 63240001-6.osm.pbf each having non-zero size, but when I am running mkgmap 6-th img file having size 0 bytes.

When I check my map in qlandkartegt it looks like it is created by 5 tiles.

Any idea what is wrong?

mira

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#4 2012-10-10 10:01:04

Re: Greenland map problem

My experience is that --overlap=10000 can lead to some problems, maybe try to lower this value (5000?)

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#5 2012-10-13 21:38:37

Re: Greenland map problem

ligfietser wrote:

My experience is that --overlap=10000 can lead to some problems, maybe try to lower this value (5000?)

I finally get time to try again ... The problem was in splitter but in "max-nodes" value.
I didn't noticed message after build of map:

There is not enough room in a single garmin map for all the input data
   The .osm file should be split into smaller pieces first.

Usually map wasn't build with this kind of error before so I didn't expect this kind of problem.
Maybe something changed in mkgmap

I lowered value in "max-nodes" from 900000 to 700000 to solve this. Hmmm I used even 1600000 value before without problem

thank you

mira

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#6 2012-10-13 22:49:17

Re: Greenland map problem

Hi,

Next ugly issue with Greenland map I have is with huge glacier polygon.
Greenland is covered by huge glacier (cca 90%), but I can see just more or less eastern half of it.
I was trying different value for splitter "overlap" and fixed max-nodes=700000 ... values between 6000 and 10000 for "overlap" will give me same result of seeing eastern half of glacier with other values I don't see this glacier at all.

I know that splitter have problem with big polygons, but anyway maybe this "glacier issue" can fixed somehow?
http://www.mkgmap.org.uk/pipermail/mkgm … 15031.html

Any workaround?

regards

mira

Last edited by miramikes (2012-10-13 23:05:52)

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#7 2012-10-19 12:36:32

Re: Greenland map problem

miramikes wrote:

Next ugly issue with Greenland map I have is with huge glacier polygon.

Hi,

I got a great improvement of this issue with this patch:
http://www.mkgmap.org.uk/pipermail/mkgm … 15152.html

With this line in my problem_polygons.txt
rel:1279614 # Greenland glacier

Results varies on splitter values max-nodes and overlap
To get best result i run:  --max-nodes=30000  --overlap=5000

I usually tried splitted tiles as big as possible e.g.  --max-nodes=1000000 ... Is there any disadvantage to have a lot of small tiles?

regards

mira

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#8 2012-10-19 16:13:11

csdf
Senior Member
From: UK, living in Abu Dhabi
Registered: 2009-08-11
Posts: 314
Website

Re: Greenland map problem

I don't think there's any disadvantage to small tiles, though there may be an upper limit to how many a GPS unit can handle

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#9 2012-10-19 18:08:37

Re: Greenland map problem

I don't know, I guess the smaller the tiles, the more you have to deal with large multipolygons that are larger than the tiles and will be broken? hmm

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#10 2012-10-20 14:53:05

Re: Greenland map problem

ligfietser wrote:

I don't know, I guess the smaller the tiles, the more you have to deal with large multipolygons that are larger than the tiles and will be broken? hmm

This sounds logical, but for unknown reason if I keep tiles bigger I still missing southern tip of Greenland glacier.
Maybe some havoc in osm data or I  have to add some more relations to my problem_polygons.txt  ... I have to investigate this more. sad

mira

Last edited by miramikes (2012-10-20 15:03:09)

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#11 2012-10-20 14:54:05

Re: Greenland map problem

csdf wrote:

I don't think there's any disadvantage to small tiles, though there may be an upper limit to how many a GPS unit can handle

What is usual limit? I have Garmin 78.

Thank you.

mira

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#12 2012-10-24 00:09:06

Re: Greenland map problem

miramikes wrote:
ligfietser wrote:

I don't know, I guess the smaller the tiles, the more you have to deal with large multipolygons that are larger than the tiles and will be broken? hmm

This sounds logical, but for unknown reason if I keep tiles bigger I still missing southern tip of Greenland glacier.
Maybe some havoc in osm data or I  have to add some more relations to my problem_polygons.txt  ... I have to investigate this more. sad

mira

I got this issue fixed by newest "splitter_problem_list_v2.patch"

http://www.mkgmap.org.uk/pipermail/mkgm … 15195.html

So I now staying with bigger tiles happily big_smile "--max-nodes=700000"

mira

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