cut applied to date-time objects.
"cut"(x, breaks, labels = NULL, start.on.monday = TRUE, right = FALSE, ...)
"cut"(x, breaks, labels = NULL, start.on.monday = TRUE, right = FALSE, ...)"POSIXt" or "Date".x is to be cut into or an
interval specification, one of "sec", "min",
"hour", "day", "DSTday", "week",
"month", "quarter" or "year", optionally
preceded by an integer and a space, or followed by "s".
For "Date" objects only "day", "week",
"month", "quarter" and "year" are allowed.
right). If
labels = FALSE, simple integer codes are returned instead
of a factor.
breaks = "weeks", should the
week start on Mondays or Sundays?labels = FALSE which returns
the integer level codes.
right = TRUE and include.lowest = TRUE
will include both ends of the range of dates. Using breaks = "quarter" will create intervals of 3 calendar
months, with the intervals beginning on January 1, April 1,
July 1 or October 1, based upon min(x) as appropriate.
A vector breaks will be sorted before use: labels will
then correspond to the sorted vector.
seq.POSIXt, seq.Date, cut
## random dates in a 10-week period
cut(ISOdate(2001, 1, 1) + 70*86400*stats::runif(100), "weeks")
cut(as.Date("2001/1/1") + 70*stats::runif(100), "weeks")
# The standards all have midnight as the start of the day, but some
# people incorrectly interpret it at the end of the previous day ...
tm <- seq(as.POSIXct("2012-06-01 06:00"), by = "6 hours", length.out = 24)
aggregate(1:24, list(day = cut(tm, "days")), mean)
# and a version with midnight included in the previous day:
aggregate(1:24, list(day = cut(tm, "days", right = TRUE)), mean)
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