Several Useful R Functions

Maelle Salmon shows off four useful R functions:

Recently I caught myself using which(grepl(...)),

animals <- c("cat", "bird", "dog", "fish")
which(grepl("i", animals))
#> [1] 2 4

when the simpler alternative is

animals <- c("cat", "bird", "dog", "fish")
grep("i", animals)
#> [1] 2 4

Read on for another example of using grep() instead of grepl(), as well as three other functions you might want to keep in mind. H/T R-Bloggers.