如何使用R合併座標空間數據集？

Question

我在R中有兩個單獨的空間點數據幀（附圖中的紅色和黑色）。如何將數據屬性從「紅色」數據集導入R中「黑色」數據集中最近的位置？

Answer 1

下面是解決這個問題的方法之一。

library(raster) 
library(sp) 

### create some example datasets 
coords_A = cbind(runif(10, 1, 10), runif(10,1,10)) 
sp_A = SpatialPoints(coords_A) 
spdf_A = SpatialPointsDataFrame(coords_A, data.frame(varA=letters[1:10])) 

coords_B = cbind(runif(10, 1, 10), runif(10,1,10)) 
sp_B = SpatialPoints(coords_B) 
spdf_B = SpatialPointsDataFrame(coords_B, data.frame(varB=letters[11:20], varC=LETTERS[11:20])) 

### compute the complete distance matrix between the two sets of points 
dist_mat <- pointDistance(spdf_A, spdf_B, lonlat = FALSE, allpairs = TRUE) 

### identify nearest point in dataset B for every point in dataset A 
nearest <- apply(dist_mat, 1, which.min) 

### bind together the data from the dataset B (in your case the "red points") 
### at the closest point to dataset A ("black points") 
spdf_A@data<- cbind(spdf_A@data, spdf_B@data[nearest,])