Iteration

split()

{base}

divide data frame into groups in a list

map_dbl()

{purrr}

apply a function to multiple elements of an object in purrr, return a double vector

for()

{base}

control flow with for loop

map_chr()

{purrr}

apply a function to multiple elements of an object in purrr, return a character vector

map()

{purrr}

apply a function to multiple elements of an object in purrr, return a list

map_df()

{purrr}

apply a function to multiple elements of an object in purrr, return a data frame

dir()

{base}

return directories in named directory

The end!