Minus operation of data frames

Question

I have 2 data frames df1 and df2.

df1 <- data.frame(c1=c(\"a\",\"b\",\"c\",\"d\"),c2=c(1,2,3,4) )
df2 <- data.frame(c1=c(\"         


        

Answer 1

If you're not planning on using any of the actual data in d2, then you don't need merge at all:

df1[!(df1$c1 %in% df2$c1), ]