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.
Este exercício faz parte do curso
Data Manipulation with data.table in R
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
duration_stats <- batrips[___,
.(___,
___)]
duration_stats