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. Required. |
to |
end date. Optional. |
by |
increment of the sequence. Optional. See ‘Details’. |
length.out |
integer, optional. Desired length of the sequence. |
along.with |
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
difftime
A character string, containing one of
"day"
,"week"
,"month"
,"quarter"
or"year"
. This can optionally be preceded by a (positive or negative) integer and a space, or followed by"s"
.See
seq.POSIXt
for the details of"month"
.In the case
seq(from, to)
, the default forby
is"day"
(or"1 day"
).
Value
A vector of class "Date"
.
Type "integer"
is preserved.
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")
## find all 7th of the month between 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[ll > st & ll < en])