[mkgmap-dev] Misplaced boundary POI

Thu Jul 8 06:04:19 BST 2021

Hi Dave,

not sure what to do with this.
1) The points which are generated for areas are not guaranteed to be inside the area
2) We can decide to generate NO point for an incomplete or otherwise invalid type=[multipolygon|boundary] relation

reg. "The POI to the east would appear to have both Zambia and Zimbabwe assigned to it":
That's not possible.  I assume you see the popup for the boundary line.
Used echotags to check this:
boundary = administrative & mkgmap:area2poi = true & admin_level = 2               {echotags ""}[0x1400 resolution 16-20]

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von dfjkman at gmail.com <dfjkman at gmail.com>
Gesendet: Montag, 5. Juli 2021 18:54
An: mkgmap-dev at lists.mkgmap.org.uk
Betreff: [mkgmap-dev] Misplaced boundary POI

Hi Gerd,

The other day I noticed that the country name along the boundary between Zambia and Zimbabwe was misplaced in 2 regions, see the attached images. The name also switches at different detail levels in BaseCamp, at Medium and High it shows Zimbabwe north of the border and at Higher and Highest it shows Zambia. The POI to the east would appear to have both Zambia and Zimbabwe assigned to it while to the west, near Livingstone, would appear to be 2 separate POIs.

I have created a map with only the boundaries to show this clearly as it is missed when the map has more detail in it. The map was created from zambia-latest.osm.pbf from Geofabrik and split using Splitter version 615 with the following options:

java -jar -Xmx2g  C:\Users\Dave\Documents\Maps\Utils\splitter\splitter.jar
--output=pbf
                              --resolution=13
                              --description="ZM_OSM Map"
                              --wanted-admin-level=5
                              --mapid=2635
                              --max-nodes=2600000

The map was created with mkgmap-r4801, although I have noticed it with earlier versions. Options as follows:

Java -jar -Xmx7g C:\Users\Dave\Documents\Maps\Utils\mkgmap\mkgmap.jar
                              --keep-going
                              --latin1
                              --add-pois-to-areas
                              --gmapi
--style-file='C:\Users\Dave\Documents\Maps\Styles\boundaries'
                              -c C:\Users\Dave\Documents\Maps\Zambia\Split_Files\template.args
In  the basic boundary style I have the following files:
Options
               levels = 0:24, 1:22, 2:20, 3:18
               overview-levels = 4:17, 5:16, 6:15, 7:14, 8:13
Lines
               boundary=administrative & admin_level<3 [0x1e resolution 12]
Points
               boundary = administrative & mkgmap:area2poi = true & admin_level = 2               [0x1400 resolution 16-20]
               <finalize>
name = * {name '${name}'}

This is not something that overly worries me but if it happens here it may happen elsewhere and be missed. I have not analysed my maps to see if it happens with other provincial or district boundaries.
Kind regards,
Dave