I would like to do a sommation of durations in R in order to get a total one.
My data frame (simplified) looks like this:
| Name | Job # | Job duration | 
|---|---|---|
| John | 1 | 10 | 
| John | 2 | 5 | 
| Mary | 1 | 30 | 
| Bob | 1 | 7 | 
| Bob | 2 | 7 | 
| Bob | 3 | 7 | 
So, in this case, I would like to create a new variable like data$job_duration_total. For this variable, John would have a job_duration_total = 15, Mary = 30 and Bob = 21
I tried using the sum function, without success.
Any help you can provide in helping me understand is greatly appreciated!
 
    