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I have a polyline layer (pretty much an OSM network) that I need to count the total number of other link ends the primary link is attached to. In other words, I have over 59,000 links in a city network and I'm trying to measure connectivity. I want to count the number of endpoints to other links that each link is attached to.

I also need to maintain the edge IDs, which rules out the sDNA package.

I have a feeling there are python scripts I could use, but I'm not familiar with python (intermediate with R, but unfortunately no exp with igraph).

It would be great if there was a qgis version of Lines and Junctions tool from ArcGIS.

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If you are interested in any node of the line (and not only start/end), you can simply use the existing tools:

  • extract the nodes from the lines (this will transfer the line entities attributes)
  • add a unique id to the nodes (using attribute calculator)
  • then compute the distance matrix.

Once you have the matrix, you can count all cells on a given line than fulfill the condition you want (=0 for exact matching, less than d if you have a threshold d).

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sDNA Individual Line Measures will compute this for you, and I think will preserve order of the input data so you can do a table join between your input and sDNA's output to get any other link attached data (such as IDs) back again.

(Failing that you could do it with a spatial join. None of the sDNA tools change the geometry they process other than sDNA Prepare).

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