Add column to data frame based on long list and values in another column is too slow

Question

I am adding a new column to a dataframe using apply() and mutate. It works. Unfortunately, it is very slow. I have 24M rows and I am adding column based on values in a long (58

Answer 1

Try one of these alternatives using lapply :

large_df$new_c <- Reduce(`|`, lapply(large_df[, 2:3], `%in%`, long_list))

or sapply :

large_df$new_c <- rowSums(sapply(large_df[, 2:3], `%in%`, long_list)) > 0

Both of which return :

large_df
#  A B C new_c
#1 1 a e  TRUE
#2 2 b f  TRUE
#3 3 c g  TRUE
#4 4 d h FALSE