| seq.POSIXt {base} | R Documentation |
Generate Regular Sequences of Dates
Description
The method for seq for data-time classes.
Usage
## S3 method for class 'POSIXt'
seq(from, to, by, length.out=NULL, along.with=NULL, ...)
Arguments
from |
starting date. Required |
to |
end date. Optional. If supplied must be after |
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 seconds.
A object of class
difftimeA character string, containing one of
"sec","min","hour","day","DSTday","week","month"or"year". This can optionally be preceded by an integer and a space, or followed by"s".
The difference between "day" and "DSTday" is that the
former ignores changes to/from daylight savings time and the latter takes
the same clock time each day. ("week" ignores DST, but
"7 DSTdays") can be used as an alternative. "month" and
"year" allow for DST as from R 1.5.0.)
Value
A vector of class "POSIXct".
See Also
DateTimeClasses
Examples
## first days of years
seq(ISOdate(1910,1,1), ISOdate(1999,1,1), "years")
## by month
seq(ISOdate(2000,1,1), by="month", length=12)
## quarters
seq(ISOdate(1990,1,1), ISOdate(2000,1,1), by="3 months")
## days vs DSTdays
seq(ISOdate(2000,3,20), by="day", length = 10)
seq(ISOdate(2000,3,20), by="DSTday", length = 10)
seq(ISOdate(2000,3,20), by="7 DSTdays", length = 4)