Combining i and j
As you saw in an earlier exercise when you combine i and j, data.table first filters the rows in i and then applies the computation in j. This applies when calculating multiple stats as well.
Additionally, you can also specify plot(), hist() or any other plotting functions in the j argument.
Deze oefening maakt deel uit van de cursus
Data Manipulation with data.table in R
Praktische interactieve oefening
Probeer deze oefening eens door deze voorbeeldcode in te vullen.
duration_stats <- batrips[___,
.(___,
___)]
duration_stats