match two data.frames based on multiple columns

Question

My head stands still at the moment. I would like to match/extract data from a larger data.frame (df) based on the columns in a smaller data.frame (mdf). What I\'m getting st

Answer 1

In case you would use match or %in% on multiple columns you could use interaction, paste or use a list to match on multiple columns.

df[match(interaction(mdf), interaction(df[c("car_1", "car_2")])),]

df[match(paste(mdf$car_1, mdf$car_2), paste(df$car_1, df$car_2),),]

df[match(asplit(mdf, 1), asplit(df[c("car_1", "car_2")], 1)),]

df[interaction(df[c("car_1", "car_2")]) %in% interaction(mdf),]