I have a points layer and polygons layer with attributes I want to join for each point. Not all points are exactly within a polygon, so I'm looking for a way to join attributes based on nearest polygon (so that if a point is located within a polygon it will just get its attributes).
I've tried using the NNJoin plugin, but I've noticed that for lots of points that are located within a polygon, it will joing attributes of a different polygon.
[GIS] Joining points with nearest polygon using QGIS
proximityqgisspatial-join
Related Solutions
Using "Distance Matrix" you can calculate the nearest point. Make sure that both layers are in the same CRS! Then, you can load the results and use them to join table A and B.
In "Distance matrix" chose: "Linear distance matrix" and "use only the nearest k target points: 1"
Load the CSV using "Add Vector Layer" and join the layers in Layer A's layer properties - join tab.
And the result:
To join attribute from one layer to another you can click the Join attribute by location tool under the Vector tab. This will open the tool screen. Choose the Target layer which is the one you want to add data to ie Zone and the Join layer which is the layer with data you want to transfer Permits. Depending on the version of qgis you use it might be slightly different. I am running QGIS 2.18.3. Then you need to choose a Geometric predicate (not sure the exact option) you can try out one of the different options from intersect, touches, overlap or crosses. And then choose the take attribute of first located feature. Check and choose any other appropriate options form the menu and save to choice location
Best Answer
Try splitting your point data in two. First part would be the points that fall within a polygon and the second part would be points falling outside polygons. For the first part, perform a regular spatial join, and for the second part, use the NNJoin plugin. You can later merge the two resulting point layers into one. This way you can avoid the plugin performing an incorrect join on some of the points that fall within a polygon.
In order to select points that fall within the polygon layer, use the Spatial Query plugin (now a core QGIS plugin), then save the selection as a new layer. Invert the selection and save it as the second layer and perform the join using the NNJoin plugin.
Note that I have never used the NNJoin plugin.