Looking through the OSMnx and OSM API documentation I haven't been able to find a reference for how to specify world place names.
The OSMnx examples use US locations, where the City, County, State, Country structure is used, but this structure doesn't apply to other countries of course.
Specifically, how should I structure this query to specify the boundary of London for instance? Or are there docs I haven't found for this yet?
G = ox.graph_from_place('London', network_type='drive')
# project the network to UTM (zone calculated automatically) then plot it
G_projected = ox.project_graph(G)
fig, ax = ox.plot_graph(G_projected)
Thanks!
This thread provides more detail about how to narrow your query. Long story short, use OSMnx's which_result argument and pass your place query as an explicit dict rather than a string to improve geocoder specificity.
Related
Does anyone have any documentation or know how to get all the house numbers of a city available on OpenStreetMap or Nominatim?
I've searched some documentation but it doesn't seem to work.
Or anyone have api documentation that can do it please help me.
Thanks,
There's no direct API for this that would just spit out all the addresses, or even just all the house numbers, for a specific city, at least not that I'd know off.
If you can import an OSM planet extract containing your city of choice into an osm2pgsql database it would be easy to run:
SELECT DISTINCT "addr:housenumber"
FROM planet_osm_point
WHERE "addr:city=..."
UNION
SELECT DISTINCT "addr:housenumber"
FROM planet_osm_polygon
WHERE "addr:city=..."
Overpass API could also be used, esp. with the OverPass Turbo frontend it can be given queries like "addr:housenumber=* in City_name", but by default it will return full object data and not just a single field like house number.
Raw Overpass API queries can probably do just that, but I'm not that deep into its query syntax. Maybe the examples can give you a hint towards what may work.
But the Overpass API query language is not necessarily for those faint at heart ... :O
I'm trying to query the OSM Overpass API to find any amenities within a bounding box. The actual query in my program will be generic but in my testing I noticed I cannot retrieve the coordinates(latitude, longitude) of any of the ways. Here is my script:
(
node
["amenity"="police"]
(39.235,-76.715,39.373,-76.525);
way
["amenity"="police"]
(39.235,-76.715,39.373,-76.525);
);
(._;>;);
out meta;
I need to use ways because I'm missing a significant amount of data without them. Unfortunately they do not include any coordinate data despite me adding out meta instead of the normal out. This was answered here, overpass-api ways query include coordinates about a year ago but that solution no longer works. Is this a bug? Or am I doing something wrong? I've also tried out center, out geom, and out skel to no success. I'm outputting the data in xml.
ANSWERED, I left on the recursion line on the end by accident. Thanks Tyr.
I want to write a code that has the Countrycode and Postcode as an input and the ouput are the streets that are in the given postcode using some apis that use GSM.
My tactic is as follows:
I need to get the relation Id of the district. For Example 1991416 is the relation id for the third district in Vienna - Austria. It's provided by the nominatim api: http://nominatim.openstreetmap.org/details.php?place_id=158947085
Put the id in this api url: http://polygons.openstreetmap.fr/get_wkt.py?id=1991416¶ms=0
After downloading the polygon I can put the gathered polygon in this query on the overpass api
(
way
(poly: "polygone data")
["highway"~"^(primary|secondary|tertiary|residential)$"]
["name"];
);
out geom;
And this gives me the streets of the searched district. My two problems with this solution are
1. that it takes quite a time, because asking three different APIs per request isn't that easy on ressources and
2. I don't know how to gather the relation Id from step one automatically. When I enter a Nominatim query like http:// nominatim.openstreetmap.org/search?format=json&country=austria&postalcode=1030 I just get various point in the district, but not the relation id of the searched district in order to get the desired polygone.
So my questions are if someone can tell my how I can get the relation_Id in order to do the mentioned workflow or if there is another, maybe better way to work this issue out.
Thank you for your help!
Best Regards
Daniel
You can simplify your approach quite a bit, down to a single Overpass API call, assuming you define some relevant tags to match the relation in question. In particular, you don't have to resort to using poly at all, i.e. there's no need to convert a relation to a list of lat/lon pairs. Nowadays the concept of an area can be used instead to query for certain objects in a polygon defined by a way or relation. Please check out the documentation for more details on areas.
To get the matching area for relation 1991416, I have used postal_code=1030 and boundary=administrative as filter criteria. Using that area you can then search for ways in this specific polygon:
//uncomment the following line, if you need csv output
//[out:csv(::id, ::type, name)];
//adjust area to your needs, filter critera are the same as for relations
area[postal_code=1030][boundary=administrative]->.a;
// Alternative: {{geocodeArea:name}} -> see
// http://wiki.openstreetmap.org/wiki/Overpass_turbo/Extended_Overpass_Queries
way(area.a)["highway"~"^(primary|secondary|tertiary|residential)$"]["name"];
(._;>;);out meta;
// just for checking if we're looking at the right area
rel(pivot.a);out geom;
Try it on overpass turbo link: http://overpass-turbo.eu/s/6uN
Note: not all ways/relations have a corresponding area, i.e. some area generation rules apply (see wiki page above). For your particular use case you should be ok, however.
I would like to find an API that would return a city's area in square feet, square miles, square meters or any area unit given only the city name.
For example, I query "san francisco" and I get something back like "231.89 sq mi or 600.6 km2".
I need this data for US and Canadian cities for now but it would be nice to have an API that covers any city in the world.
I'd rather avoid scraping wikipedia or any other website and use a proper API if at all possible.
You can use DBpedia to get this information. An example of a SPARQL query to get this information would be:
select ?area where { dbr:San_Francisco dbo:areaTotal ?area }
I am working on a project where we are going to be looking at finding the shortest/fastest route from point A to point B. I've been looking at the tables generated by the osm2pgsql. And I'm wondering how would I represent a road obstructed after the osm has been loaded into our database. Our project will rely on osm to map out all of the roads we will also have an operator looking at live video footage of roads. At which point if the operator see's a road is obstructed we want to update the database to reflect this road obstructed say by a downed tree.
I've been looking at all of the columns and the only one that stands out in my head is barrier. I have been unable to find any documentation on what each column represents and how pg_route takes each into consideration when creating a route. What I'm looking for is a column that when pg_route looks in the database and sees a road it says oh that roads blocked skip it?
This is good question for gis.se...
First thing is pg_routing can't route via data generated by osm2pgsql - this data is not a network. You need data generated by osm2po or osm2pgrouting and this data is quite different.
Second thing is - there is no such column. In every pg_routing function you're passing sql which will select data for route search so you're deciding which edge will be in this dataset and which not - it's not a problem to add extra column to table with edges.
Here is link to pgrouting workshop it will guide you through all process from import of data to first generated route. It's using osm2pgroutin to import data, but I suggest you use osm2po instead.
So as Jendrusk mentioned, when you generate a route you will pass the function a SQL query to select the edges for the graph you want to solve, 'select * from edges where the_geom && <bbox>' You can model blockages using point and radius, lines, or polygons that you want the route to avoid by adding to the query above avoidance zones like:
'select * from edges where the_geom && <bbox> and not st_dwithin(the_geom, point, radius) and not stdwithin(the_geom, line_or_polygon, 0.0)'
If you have lots of these avoidances then put them in a table and do a join to eliminate the edges that are used to build the graph. If the edges are not there the route is forces to find a way around the avoidance.