Looking at the _gnm_graph table, I think that is the issue. THere are some
connections, but only 8 out of ~300 points.
Is it required that the points layer be on the end of a line? The points
layer I have are on top of the lines, however a single line may have
multiple points along its length.
Thanks for the response. The source data is in EPSG 900913, the network data
according to ogrinfo:
PROJCS[WGS_84_Pseudo_Mercator,
GEOGCS[GCS_WGS_1984,
DATUM[WGS_1984,
SPHEROID[WGS_84,6378137,298.257223563]],
PRIMEM[Greenwich,0],
The topology building algorithm firstly takes one of the line features,
determines its start and end point coordinates, than forms two areas with
the center in those points and in size with the snap tolerance value and
than searches two point features which are situated in the formed areas.
The
No, it will not break the line into segments. All point features that are
geometrically on the line feature except endings will be ignored.
For Y intersection the connections will be created only for 3 lines with
the common end point.
2015-03-11 14:28 GMT+04:00 ChiefDan chief...@gmail.com:
Hi,
I also would like to note, that this is the simple and sample algorithm.
You free to use the GNM API to create more complex connections. For
example, the GNM allows to connect some polygons (i.e. countries)
without physical geometry intersect/connect (logical connection). So,
you have
Thanks for the info!
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Hello, Dan.
Have you checked whether the _gnm_graph table had been populated
successfully? May it be void? The possible reason of this can be that the
points are too far from the line ends so you could check if you have set
an appropriate for your data snap tolerance value.
2015-03-10 2:50
I'm trying to use the GNM API to create a graph of a line layer and point
layer.
I assume I successfully build the network as I have the shapefiles output in
the directory.
When I try to find a path between 2 GFID's, I always get the void layer(no
path found).
I am not certain, but the GFIDs I am
One thing when building the network I did not do was use CreateRule to add
costs to paths as this does not make sense in my use case.
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