Computing in j (II)
In the last exercise, you performed computations in j which returned only a single value, a vector of length one. However, you often perform computations which return more than one value. The good news is that the syntax for these calculations is still the same!
You will use the difftime() function in this exercise to calculate the difference in minutes between the trips. difftime() needs two required arguments, time1 and time2 to calculate the difference (time1 - time2). To calculate the difference in minutes, set the units argument to "min":
date1 <- "2018-12-20 11:30:00 EST"
date2 <- "2018-12-20 11:20:00 EST"
difftime(date1, date2, units = "min")
Time difference of 10 mins
Deze oefening maakt deel uit van de cursus
Data Manipulation with data.table in R
Oefeninstructies
Calculate the difference in minutes between end_date and start_date.
Praktische interactieve oefening
Probeer deze oefening eens door deze voorbeeldcode in te vullen.
# Compute duration of all trips
trip_duration <- batrips[, difftime(___)]
head(trip_duration)