Modify

Sometimes we might want the output to be the same as the input, then in that case we can use the modify function rather than map

df <- data.frame(x=1:3,y=6:4)

map(df, .f=~.x*3)
#> $x
#> [1] 3 6 9
#> 
#> $y
#> [1] 18 15 12

modify(.x=df,.f=~.x*3)
#>   x  y
#> 1 3 18
#> 2 6 15
#> 3 9 12

Note that modify() always returns the same type of output (which is not necessarily true with map()). Additionally, modify() does not actually change the value of df.

df
#>   x y
#> 1 1 6
#> 2 2 5
#> 3 3 4