I am trying to create isochrones using OSM data for Indianapolis. I am trying to create an isochrone using pgrouting 2.0 with the following code. I got the code from the following tutorial
First I create a topology
select pgr_createTopology('network.publictransport', 0.0001, 'geom','id'); I played around with the tolerances a bit. I also tried using osm_target_id and osm_source_id provided by osm as the source target. I had to renumber target and source to get the numbers small enough.
create table public.indyisochrone as SELECT seq, id1 AS node, id2 AS edge, di.cost, geom_way FROM pgr_drivingdistance( 'SELECT id, source, target, km as cost FROM indianapolis', 1, .25, false, false ) as di JOIN indianapolis pt ON di.id1 = pt.id; The set of results produced by this code is obviously wrong. When I look at the map, nodes that are certainly less than .25 km away are not marked, while certain nodes 5 or 6 km are marked as part of the isochrone. I have no idea why?
The odd thing is that I have used pgr_dijkstra and that seems to be working just fine. Not sure why pgr_driving distance is getting me the wrong result.
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First I create a topology
select pgr_createTopology('network.publictransport', 0.0001, 'geom','id'); I played around with the tolerances a bit. I also tried using osm_target_id and osm_source_id provided by osm as the source target. I had to renumber target and source to get the numbers small enough.
create table public.indyisochrone as SELECT seq, id1 AS node, id2 AS edge, di.cost, geom_way FROM pgr_drivingdistance( 'SELECT id, source, target, km as cost FROM indianapolis', 1, .25, false, false ) as di JOIN indianapolis pt ON di.id1 = pt.id; The set of results produced by this code is obviously wrong. When I look at the map, nodes that are certainly less than .25 km away are not marked, while certain nodes 5 or 6 km are marked as part of the isochrone. I have no idea why?
The odd thing is that I have used pgr_dijkstra and that seems to be working just fine. Not sure why pgr_driving distance is getting me the wrong result.
- I am using ubuntu 15.04 and Ubuntu 9.4
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