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  • #29988

    Mabel
    Teilnehmer

    I am totally ignorant of map technology so please forgive my dummy question: why are not the names on the map available for searching? It seems so silly to always have to use some online service to search my offline map – especially as I use your beautiful maps (thanks!) often in areas where I can’t connect.
    (Sorry for writing this in English; my German is mediocre, aber ich kann antworten in Deutch verstehen.,)
    Mabel

    • Dieses Thema wurde geändert vor 3 Monate, 1 Woche von  Mabel.
    #30000

    mbe57
    Teilnehmer

    Hi Mabel,
    OAM provides the map data in as vector data in those .map files.
    But it is always and only the geo APP that does the handling of this data. Rendering for human viewing in particular.
    The structure of the map data in those files is targeted towards this purpose. And it is not a database that would allow efficient searching.
    Thta is the reason why e.g. Locus provides their own .map files, accompagnied by .db files for POIs and address search. Different purpose -> different file structure.
    With Locus you can combine OAM vector maps with their .db file, if you follow the naming convention of the two files.
    Cheers
    Michael

    #30002
    Tobias
    Tobias
    Moderator

    With apps like Cruiser or OruxMaps you can also use the POI files provided with the V4 maps downloads (or download separately) . When using the category 260, you can search just for place names.

    Developer of Elevate mapstyle

    #30006

    mbe57
    Teilnehmer

    Tobias, are those all STREET names or only the POI names ?

    #30008
    Tobias
    Tobias
    Moderator

    Tobias, are those all STREET names or only the POI names ?

    Do you mean searching for street names? The question of this thread concerned place names, so that’s what I was writing about.
    Advanced searching requires special POI-files (and maybe additional work from the app GUIs):
    https://groups.google.com/forum/#!searchin/mapsforge-dev/addr$3Astreet$20poi%7Csort:date/mapsforge-dev/a2OQF8qxEyk/8ZPgJM0FAwAJ

    Developer of Elevate mapstyle

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    #30011

    Mabel
    Teilnehmer

    Maybe the word ‚place names‘ wasn’t clear enough, sorry. Let me clarify: I want to search in the NAMES ON THE MAP.

    @mbe57 Thanks for the answer! I think I understand it somewhat, but not fully. Please forgive me for asking some more questions.
    1. As I was told by the maker of one app, mapsforge is not only a map-format but also a set of (java) routines to handle these data. Apperently – at least that is what I make of it – there is no routine to ‚extract‘ the placenames from the map file and that is the reason why (apparently) no app makes them searcheable. Does this make sense to you?
    2. Thanks for the tip about Locus, an app I don’t know. Some apps (Cruiser, Cartograph and Locus as well, probably) can load the separate POI files OSM provides and these can be searched. The result is not at all what I mean (see below) but I point to the principle: if a (huge) POI overlay can be quickly searched, then why not ‚convert‘ the names on the map to a POI file? It would at least be a ‚universal format‘. Maybe it could even be made ‚on the fly‘ but if not they could be made available for download. Or a utility could be made to extract the names and write a POI file. (I’m just phantasising now.)

    @tobias I don’t know Oruxmaps, but I tried Cruiser and Cartograph; both on my laptop and on my phone. Searching the POI overlay is indeed fast. BUT for searching a name on the map it is almost totally unuseable.
    The problem is that these POI files a) do not contain all the placenames on the map and b) contain a myriad of names which are NOT on the map (restaurants, businesses etc.)
    Moreover, the search mechnisms for both apps I tried are not at all geared toward this purpose. Not only very time consuming to use, but also giving either hundreds of hits (not on the map) or no hits at all when you don’t know which ‚categories‘ to search for (town? or is it a city? or a village?). Rivers and waterways do not even have a category! (And are not in the POI overlay)

    On the other hand, on-line services do a far better job. Backcountry Navigator uses ‚google location services‘ which works kind-of OK but doesn’t find all the names on the map; notably not (o irony) in nature reserves and backcountry areas. Cruiser can not connect to an on-line service. Cartograph does best in this respect as it allows connecting to the ‚OSM Nominatim‘ service which apparently contains the names on OSM maps. But (like Google) the request is not linked to the map I’m using so it finds names all over the world which can be a terrible hassle.

    So, if the names are available on-line from ‚OSM Nominatim‘, why not off-line and per map? Hence my suggestions in my answer to @mbe57. Think of an old fashioned paper atlas: would you buy one without an extensive index at the back?

    Hans

    #30013

    mbe57
    Teilnehmer

    Hi Hans,
    yes, Mapsforge is a format PLUS a Java library. But I am not aware of a database style query API for .map file content (the names are all there,, but sequential searching through a large .map file is not a smart idea …).
    So, to allow users a query for street/town requires additional efforts. To build a database that the app then can query.
    This is what Locus does. Cruiser does not, only handles Mapsforge POI files. Which Locus cannot handle (yet). They put POIs and addresses into that extra DB file.
    Indeed there would be a way to extract street/town pairs from the OSM raw data and feed that into a Mapsforge POI file, but I never tried that.
    When I go offline, I have my go-to places prepared in my Locus points database (not to be confused with POIs).
    And in addition I use the ad hoc online address search in case of unexpected needs.
    And if I would be REALLY in the very wild, I would hardly care about street names :-)
    But maybe you have a different use case in mind.
    Cheers
    Michael

    #30042
    Tobias
    Tobias
    Moderator

    POI files aren’t as sophisticated as the maps yet; they don’t contain all the same content etc. It would need a lot more work, but they are usable at the moment. The map can’t be converted, this has to be made in a separate process, and with every change in the map file this also has to be adapted. Our resources are limited, maybe we’ll find some time for it. I know there are things missing and bugs in it.

    Also the user interface of the app for searching pois can differ a lot, with OruxMaps you have more options and the categories are nested (in comparison to Cruiser), and you get search results as a list sorted by distance. As Cartograph is a paid app I can’t test how it’s there.

    It also makes sense to include things in POIs which don’t make such sense to show on the map, e.g. bicycle parking spaces. Also don’t forget that with modern mapstyles a a lot of items on the maps can be switched on/off or it depends on the used mapstyle. So to expect the additional databases to show exactly the content how the map is presented at the moment on your screen (or even at this zoom level) is very specific and not limiting the possibilities, and wouldn’t justify the amount of work to achieve this (e.g. mapstyle should be interpreted by the database search engine to filter the results – this isn’t available in mapsforge).

    Developer of Elevate mapstyle

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