R, conditionally remove duplicate rows

Question

I have a dataframe in R containing the columns ID.A, ID.B and DISTANCE, where distance represents the distance between ID.A and ID.B. For each value (1->n) of ID.A, there ma

Answer 1

One possibility:

myDF <- myDF[order(myDF$ID.A, myDF$DISTANCE), ] 

newdata <- myDF[which(!duplicated(myDF$ID.A)),]

Which gives :

    ID.A ID.B DISTANCE
1    1    3      1.0
2    2    6      8.0
5    3    2      0.4
6    4    8      7.0
7    5    2     11.0