Adding a new column
As mentioned in the video, data.table does not have to deep copy objects in order to modify them. It can modify objects by reference (inplace) to save memory and runtime using the := operator. When you update a data.table by reference, you don't have to assign the result to a new object as the original data.table is modified directly.
This exercise is part of the course
Data Manipulation with data.table in R
Exercise instructions
Add a new column duration_hour to batrips by reference, by dividing the duration column by 3600.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Add a new column, duration_hour
___[, ___ := ___]