How to Get distance time and class through OpenstreetmapX?

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I've been trying to query some edge information from an exported network from Openstreet map via this package OpenstreetmapX.jl . However, it appears that some functionality are not directly available. For instance:

Suppose you have a set of links in the form of Vector{Tuple{Int64, Int64}} and you wish to identify their distance, travel time, and class type. I know for the distance you can call something like the following command:


Links = [(301972446, 60649731)
 (60649731, 301972446)
 (2505989518, 2489651510)
 (2489651510, 60649731)
 (60649731, 301972503)
 (267224410, 2895172669)
 (2895172669, 267224410)
 (582794232, 582794289)]

# for example to know the distance of the first edge in Link set

distance(map.nodes[links[1][1]],map.nodes[links[1][2]] )

But this is not efficient. Is there anything that directly return the distance, time, and class of each edges? Like:

distance( (582794232, 582794289))
distance( links[1])
time(links[1])
class(links[1])
julia openstreetmap
1 Answers

You will need to access the MapData struct (type ?MapData for details).

Edges

Suppose you have a map:

using OpenStreetMapX
m = get_map_data(joinpath(dirname(pathof(OpenStreetMapX)),"..","test/data/reno_east3.osm");use_cache=false);

All edges are just a Vector

julia> links = m.e[1:2]   # sample 2 edges on map
2-element Vector{Tuple{Int64, Int64}}:
 (2441017888, 2975020216)
 (139988738, 385046328)

Edge classes

Edge classes are also a vector so for the above example you could do m.class[1:2]. Or you could search the id on the edge list:

 m.class[findfirst(==((140044645, 140044632)), m.e)]

This yields class number - for translation to class name use OpenStreetMapX.ROAD_CLASSES

Edge lenghts

The distances are available in w matrix, so you can do:

julia> m.w[m.v[140044645], m.v[140044632]]
41.239883456012905

You can also recalculate it using distance function:

julia> distance(m.nodes, [(140044645, 140044632)])
1-element Vector{Float64}:
 40.99997118352562

You might notice that this value is slightly lower as the distance function just calculates a stright line distance. However the get_map_data function when parsing the map, by default compresses irrelevant edges (the parameter only_intersections=true), and the distances in w are calculated before compression. In other words w includes curvature of the road and distance is just a straight line.

Travel times

You can get the travel times for edges at once:

julia> OpenStreetMapX.network_travel_times(m)
4220-element Vector{Float64}:
  1.5857447369115734
  2.3649894625077863
 ...

Routing

Finally, you can use A-star algorithm to find a distance between any two nodes:

julia> shortest_route(m, 140044645, 140044632)
([140044645, 140044632], 41.239883456012905, 1.4846358044164647)

The returned tuple contains:

  • the shortest route (nodes)
  • the distance in meters
  • the driving time in seconds
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