sp (version 0.9-24)

zerodist: find point pairs with equal spatial coordinates

Description

find point pairs with equal spatial coordinates

Usage

zerodist(obj, zero = 0.0) 
zerodist2(obj1, obj2, zero = 0.0) 
remove.duplicates(obj, zero = 0.0, remove.second = TRUE)

Arguments

obj
object of, or extending, class SpatialPoints
obj1
object of, or extending, class SpatialPoints
obj2
object of, or extending, class SpatialPoints
zero
distance values less than or equal to this threshold value are considered to have zero distance (default 0.0)
remove.second
logical; if TRUE, the second of each pair of duplicate points is removed, if not the first

Value

  • pairs of row numbers with identical coordinates; matrix with zero rows if no such pairs are found. For zerodist, row number pairs refer to row pairs in obj. For zerodist2, row number pairs refer to rows in obj and obj2, respectively.

Examples

Run this code
data(meuse)
summary(meuse)
# pick 10 rows
n <- 10
ran10 <- sample(nrow(meuse), size = n, replace = TRUE)
meusedup <- rbind(meuse, meuse[ran10, ])
coordinates(meusedup) <- c("x", "y")
zd <- zerodist(meusedup)
sum(abs(zd[1:n,1] - sort(ran10))) # 0!
# remove the duplicate rows:
meusedup2 <- meusedup[-zd[,2], ]
summary(meusedup2)
meusedup3 <- subset(meusedup, !(1:nrow(meusedup) %in% zd[,2]))
summary(meusedup3)
coordinates(meuse) <- c("x", "y")
zerodist2(meuse, meuse[c(10:33,1,10),])

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