Exercise

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.

Instructions 1/2

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1
Calculate the minimum and maximum duration for all trips where the start_station is "Townsend at 7th" and the duration is less than 500. Rename these columns to min_dur and max_dur, respectively.
2
Now for the same subset of data, plot a histogram of duration.