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.
This exercise is part of the course
Data Manipulation with data.table in R
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
duration_stats <- batrips[___,
.(___,
___)]
duration_stats