[R-sig-Geo] For each point, distance to nearest point in second dataset

[Nick Eubank]

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
>>>
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>>>
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>> --
>> Dr. Michael Sumner
>> Software and Database Engineer
>> Australian Antarctic Division
>> 203 Channel Highway
>> Kingston Tasmania 7050 Australia
>>
>>

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