Top Answers

1. Returning the matched string from a grepl match of multiple strings, rather than the logical
   6 votes
2. change parameters of a function inside that function
   4 votes
3. Using ifelse in R when one of the options produces NAs?
   4 votes
4. Listing all combinations in R
   3 votes
5. Create a new data frame cleaning NA and updating by column in r
   2 votes