Why doesn't the cut at "3 months" produce labels as expected?
# create time series data
everyday <- seq(from = as.Date('2014-1-1'), to = as.Date('2014-12-31'), by = 'day')
# create a factor based on the quarter of the year an observation is in:
qtrs <- cut(everyday, "3 months", labels = paste0('Q', 1:4))
## Error in cut.default(unclass(x), unclass(breaks), labels = labels,
## right = right, :
## lengths of 'breaks' and 'labels' differ
The cut is every 3 months, so that would create 4 Quarters and I'd expect to need 4 labels, but the error message suggests that the length of breaks and labels differs.
qtrs <- cut(everyday, "3 months", labels = paste0('Q', 1:5))
table(qtrs)
## qtrs
## Q1 Q2 Q3 Q4 Q5
## 90 91 92 92 0
The fifth label Q5 seems to be needed and yet appears with a zero count.
The example is taken from "Data Manipulation with R" by Phil Spector,
http://www.springer.com/statistics/computational+statistics/book/978-0-387-74730-9
