The data:
dat <- read.table(text="
LAT LONG
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4170
13.5330 -15.4170
13.5330 -15.4170
13.5340 -14.9350
13.5340 -14.9350
13.5340 -15.9170
13.3670 -14.6190", header = TRUE)
These commands create an id variable starting with 1:
comb <- with(dat, paste(LAT, LONG))
within(dat, Cluster_ID <- match(comb, unique(comb)))
The output:
LAT LONG Cluster_ID
1 13.533 -15.418 1
2 13.533 -15.418 1
3 13.533 -15.418 1
4 13.533 -15.418 1
5 13.533 -15.417 2
6 13.533 -15.417 2
7 13.533 -15.417 2
8 13.534 -14.935 3
9 13.534 -14.935 3
10 13.534 -15.917 4
11 13.367 -14.619 5
