R Remove rows if value in one column appears again in another column without loop [duplicate]

This question already has an answer here:

I would like to remove cases where the combination of two columns also appears as a reverse combination in those two same columns

Below is the input and desired output.

SS of Tables

It doesn't matter if the first or second occurrence is kept.

Data:

df <- data.frame( "x1" = 1:6, "x2" = c(2,1,4,3,6,5), "x3" = c("a","b", "c","d","e","f"))

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Can you please share your example input in a format I can copy/paste in to R? Images are a very unfriendly way to share data. dput(your_input) or dput(head(you_input)) is an easy way to make a copy/pasteable R object.
– Gregor
Sep 4 '18 at 19:51

dput(your_input)

dput(head(you_input))

nopes = unname(as.list(DT[, 2:1])); res = DT[!nopes, on=names(DT)[1:2]]? Not sure if it works since there's no example to test with.
– Frank
Sep 4 '18 at 19:51

nopes = unname(as.list(DT[, 2:1])); res = DT[!nopes, on=names(DT)[1:2]]

Sure, Try this: df <- data.frame("x1" = 1:6, "x2" = c(2,1,4,3,6,5), "x3" = c("a","b", "c","d","e","f"))
– a.m.
Sep 4 '18 at 20:30

with that data, you can do subset(df,!duplicated(t(apply(df[-3],1,sort))))
– Onyambu
Sep 4 '18 at 21:07

subset(df,!duplicated(t(apply(df[-3],1,sort))))

df[!duplicated(t(apply(df[-3],1,sort))),]
– Onyambu
Sep 4 '18 at 21:08

df[!duplicated(t(apply(df[-3],1,sort))),]

1 Answer
1

The first suggestion worked just fine for me:

subset(df,!duplicated(t(apply(df[-3],1,sort))))

搜尋此網誌

Dfyjkt