Map simplification?
  • Hi,

    I assume that you use the "(Ramer–)Douglas–Peucker" algorithm in your map generation to simplify ways and so on, but how does that work in your map generation process?
    I'm sure I did some "tagging" to (small) road segments. If you (MapFactor) simplify these roads (OSM ways), do you simply remove parts and thereby lose some of the tagging, or do you only simplify ways with the same tagging?

    If you have something like
     _____X                      |
       A   B      C         D      E

    A-E way segments (road segments); X the nodes.
    You could simplify C & D into one way part, but if D has different tagging (like turn=, turn:lanes=, destination:lanes=, destination:ref:lanes= and destination:int_ref:lanes=) which are normally in the last part of a way before a junction, you would lose these if you simply only looked at simplifying the curve in the way.
    I did some heavy tagging up to 30 August. All tagging is there in OSM, but it is not always reflected in the Navigator maps.

    So: how do you process (linear) curves (if you use Ramer–Douglas–Peucker)?

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  • Hi hvdwolf,
    can you give me some way/node IDs as an example? Yes, I think that we use "Doublas-Peucker" for some shapes decimation (I am not sure if streets too, but probably yes) ... but because of the routing there are no links rejected. In reality OSM ways are first split by crossings.
  • Hi,

    I'm sorry. I completely forgot to add some examples here.
    exits of the A28 through Zwolle ->
    "Knooppunt Hattemerbroek" near Zwolle ->
    "Knooppunt Beekbergen" near Apeldoorn ->

    Note: Hit the execute button (or what it's called in your language) to see which lanes have been tagged.

    Some of them work. some don't.

    Since then I did additions, corrections etc. to these and a number of others as well, both in my region as on other spots in Nederland.

  • Some of them work fine now in the new early-maps. Probably a slight mismatch between commit date and planet generation date even though it was 3 days apart.
    Some others are still not working and these are the long ones. Could it be a string length problem?
    One is for example:  destination:lanes=Apeldoorn-Zuid;Apeldoorn-West;Amersfoort;Amsterdam|Apeldoorn-Zuid;Apeldoorn-West;Amersfoort;Amsterdam|Arnhem|Zwolle.
    That's 116 characters (after the destination:lanes=). Are your string lengths 80 characters or so?

    Forgot to mention: The turn:lanes work correct.
  • Can you give me way ID for this "destination:lanes=Apeldoorn-Zuid;Apeldoor ... " example? The number of characters should be OK (there was a problem at the beginning, now the limit is 1000chars).

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