[mkgmap-dev] What should be in the global index by default?

Tue May 9 09:43:36 BST 2017

Hi Andrzej,

I've now tried with a Nüvi 2447. I did not see an effect of the index when searching for POI.
I also tried with a map created with r3909 (trunk)
It seems that the Garmin map "CN Europe NTU 2018.10 Central Region"
contains an index which allows the device to suggest names for POI similar to the search for adresses.
Means, when I search for shops it shows possible candidates while typing the name.

The interesting thing is that MapSource creates nearly the same index as mkgmap when transfering a map to my Oregon,
esp. the data regarding POIs looks equal.

I've now also created a gmapsupp of Niedersachsen with the default style (182 MB) with r3937 and with option --index.
In the address search, when I seach for a city, I can type Bux and the device jumps to the result list which 
correctly shows Buxtehude (which is the only match in that map)
without pressing any further key.
When I search for cities (as POI) I can type Bux or Buxte and nothing happens until I press the check button.
When I do that for Bux it shows me Buxtehude but also many cities Buxton around the world. Those entries are from the basemap,
and they appear even if disable the map.
While the list is shown the display shows a rotating progress indicator which probably means that the device
still scans more tiles. A search in the index would be much faster.
Question is if that is a problem in the index or in the device.

Does anybody see different results for similar test cases with an Oregon 600 ?
If yes, maybe the problem is that the default style produces bad POI entries..

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Gerd Petermann <GPetermann_muenchen at hotmail.com>
Gesendet: Sonntag, 7. Mai 2017 17:20:24
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] What should be in the global index by default?

Hi Andrzej,

thanks for the hints reg. Mapsource. I've not noticed the option "Find nearest places" (Ctrl+Shift+F).   You are right, this seems to ignore the index and shows all possible catgories
and the search field for strings is named "Containing" and works like that, "net" finds Planet and Netto.
The normal find (Ctrl+F) depends on the index. The dialog is probably created based on data in Mdr18+Mdr19, not Mdr4.

I try to get a Nüvi from my mother to find out more details. Maybe index usage also depends on the number of tiles in map.

Gerd
________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Andrzej Popowski <popej at poczta.onet.pl>
Gesendet: Sonntag, 7. Mai 2017 15:54
An: mkgmap-dev at lists.mkgmap.org.uk
Betreff: Re: [mkgmap-dev] What should be in the global index by default?

Hi Gerd,

there are 2 search algorithms in Garmin devices. One uses index, second
search near current position and probably uses data directly in img. You
can see both versions in Mapsource. Under "Find" menu there are options
"Find Places", which uses index and "Find Nearest Places", which doesn't.

If you start "Find Places", then you get 4 categories. I guess they
could represent 4 different section of index. These are: cities,
features (POIs), addresses and intersections.

Under feature you find categories and subcategories. These are device
specific, could be different in a GPS. I think categories are dependent
on index too, since map created by mkgmap behaves differently than
cgpsmapper version, even if they contain the same POIs.

Search in BaseCamp is weird. I think developers got some idea to
integrate multiple algorithms into single search. It took them years to
get it working and it still confuses me.

Search in GPS seems to work similar to Mapsource. If you search for a
name, then most probably it uses index. I'm not sure about search for a
category. I think outdoor GPS starts with search near current position
but maybe car GPS uses index.

--
Best regards,
Andrzej
_______________________________________________
mkgmap-dev mailing list
mkgmap-dev at lists.mkgmap.org.uk
http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
_______________________________________________
mkgmap-dev mailing list
mkgmap-dev at lists.mkgmap.org.uk
http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev