| seq.Date {base} | R Documentation |
Generate Regular Sequences of Dates
Description
The method for seq for objects of class
"Date" representing calendar dates.
Usage
## S3 method for class 'Date'
seq(from, to, by, length.out = NULL, along.with = NULL, ...)
Arguments
from |
starting date; optional. |
to |
end date; optional. |
by |
increment of the sequence; optional. See ‘Details’. |
length.out |
integer, optional. Desired length of the sequence. |
along.with |
optional; take the length from the length of this argument. |
... |
arguments passed to or from other methods. |
Details
by can be specified in several ways.
A number, taken to be in days.
A object of class
difftimeA character string, containing one of
"day","week","month","quarter"or"year", or apmatch()able abbreviation of these. This can optionally be preceded by a (positive or negative) integer and a space, or followed by"s".See
seq.POSIXtfor the details of"month".In the case
seq(from, to), the default forbyis"day"(or"1 day").
Value
A vector of class "Date".
Type "integer" is often preserved on purpose, saving
object.size.
See Also
Examples
## first days of years
seq(as.Date("1910/1/1"), as.Date("1999/1/1"), "years")
## by month
seq(as.Date("2000/1/1"), by = "month", length.out = 12)
## quarters
seq(as.Date("2000/1/1"), as.Date("2003/1/1"), by = "quarter")
## 3-week period ending on a fixed date
seq(to = as.Date("2024-06-18"), by = "day", length.out = 21)
## find all 7th of the month _strictly_ inside two dates, the last being a 7th.
st <- as.Date("1998-12-17")
en <- as.Date("2000-1-7")
ll <- seq(en, st, by = "-1 month")
rev(ll[st < ll & ll < en])
## can abbreviate 'month' to 'm':
identical(seq(st, en, by = "m"),
seq(st, en, by = "1 month"))