[mkgmap-dev] mkgmap memory problem with big, nearly empty tiles

Sun Jan 22 11:30:41 GMT 2012

Hi,

with my try to build a map for the whole US I run into the next
problem: some of the US is on the other side of the 180 longitude.

As result, splitter will create a really huge tile with nearly
no data. mkgmap with --index --gmapsupp needs a really huge amount
of memory for this (8 GB) and then prints:

"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."

The bbox is really big: 
<bounds minlat='-0.65' minlon='-38.9' maxlat='71.851' maxlon='180.0'/>

The data is only in a very small area of that tile. If I adjust the
bounds area, I can build the tile without problems.

Beside patching the tile after evey split, is there any way to
better split the extract with tilesplitter?

And why does mkgmap need so much memory for this tile? Is there
any way to improve the mkgmap algorithm to work with this tile?

I'm using mkgmap-r2169 and the command line is:
env MKGMAP_MEM=8000M mkgmap --style-file=style --country-name=usa --country-abbr=US --family-name=TK-OSM-US --area-name=US --latin1 --license-file=TK-USA-Basemap_license.txt '--copyright-message=OpenStreetMap.org contributors. See: http://wiki.openstreetmap.org/index.php/Attribution. TK-USA-Basemap based on data from 2012-01-20.' --series-name=TK-USA-Basemap --bounds=bounds --location-autofill=bounds,nearest,is_in --add-pois-to-areas --reduce-point-density-polygon=8 --min-size-polygon=8 --make-opposite-cycleways --remove-short-arcs --adjust-turn-headings --route --net --generate-sea=extend-sea-sectors '--pois-to-areas-placement=entrance=main;entrance=yes;building=entrance;barrier=entrance' --index -c mkgmap.cfg --gmapsupp --input-file=verybigbb.osm  --description=TK-USA-Basemap

The sources can be found at: http://osm.thkukuk.de/tmp/bbox.tar.gz

 Thanks,
   Thorsten
-- 
Thorsten Kukuk, Project Manager/Release Manager SLES
SUSE LINUX Products GmbH, Maxfeldstr. 5, D-90409 Nuernberg
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 16746 (AG Nürnberg)