数据帧的R匹配/％in％

Question

I'm trying to find those rows in a data frame, which appear in another data frame.

df1 <- data.frame(V1=c(0,1,1,1), V2=c(0,1,0,2))
df2 <- data.frame(V1=c(0,1), V2=c(0,1))

in_df(df1, df2) # should yield c(T, T, F, F)

Is there a function which calculates this?

Answer 1

Try

as.character(interaction(df1)) %in% as.character(interaction(df2))
#[1]  TRUE  TRUE FALSE FALSE

Answer 2

There is a duplicated.data.frame method that can be combined with rbind :

in_df <- function(d1,d2) duplicated(rbind(d2,d1))[-(1:nrow(d2)) ]
in_df(df1, df2)
#[1]  TRUE  TRUE FALSE FALSE