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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

View Course

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

duration_stats <- batrips[___, 
                          .(___, 
                            ___)]
duration_stats
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