For each point, distance to nearest point in second dataset
For other's reference, that was almost right: To get distance from each voter to closest polling place, the syntax was: knn.results = knn(data=coordinates(polling.places), query=coordinates(voters), k=1)
On Thu, May 19, 2016 at 3:03 PM Nick Eubank <nickeubank at gmail.com> wrote:
Thanks Michael!
Super easy context: two SpatialPointsDataFrames ("voters",
"polling.places"). Each has coordinate columns "x" and "y".
Is it just:
library(nabor)
knn(voters, query = polling.places, k=1)
?
On Thu, May 19, 2016 at 2:59 PM Michael Sumner <mdsumner at gmail.com> wrote:
Use nabor package, it takes a little to learn but is crazy fast. Happy to show if you make a relevant example. Mike On Fri, May 20, 2016, 06:42 Nick Eubank <nickeubank at gmail.com> wrote:
Hi All, Trying to an equivalent to the "nearest" tool in ArcGIS for two SpatialPointDataFrames. I can do the naive implementation by calculating all pairwise distances using gDistance and taking the min, but I have some huge datasets and was looking for something more efficient. (For example, here's a trick with knearneigh for points in same dataset ( http://gis.stackexchange.com/questions/132384/distance-to-nearest-point-for-every-point-same-spatialpointsdataframe-in-r )). Any suggestions? Thanks! Nick [[alternative HTML version deleted]]
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