| as.Date.numeric {zoo} | R Documentation |
Functions to convert numeric and related classes to objects of
class "Date" representing calendar dates.
## S3 method for class 'numeric': as.Date(x, origin = "1970-01-01", ...) ## S3 method for class 'ts': as.Date(x, offset = 0, ...)
x |
numeric or an object of class "ts", respectively. |
origin |
A specification of the origin for the dates (x days since origin). |
offset |
A value added to time(x). |
... |
Further arguments. Currently not used. |
The as.Date method for numeric arguments x interprets x
the number of days since the origin (default: 1970-01-01).
Negative values are allowed.
The as.Date.ts inspects time(x) and frequency(x):
If the frequency is 1 or 4 or 12, time(x) is regarded to be annual,
quarterly or monthly data respectively. If the frequency is something else,
no coercion is done.
The as.Date methods return an object of class "Date".
In the case of as.Date.ts applied to a yearly, quarterly or monthly
series the earliest date, i.e., first of year, quarter or month, is returned.
Date for details of the date class
as.Date(0) # uses origin = "1970-01-01" # all three result in origin and next 9 days as.Date(0:9) as.Date(0) + 0:9 x <- ts(rnorm(10), start = 0) as.Date(unclass(time(x))) # annual/quarterly/monthly series: xa <- ts(rnorm(10), start = 2001) xq <- ts(rnorm(10), start = 2001, freq = 4) xm <- ts(rnorm(10), start = 2001, freq = 12) as.Date(time(xa)) as.Date(time(xq)) as.Date(time(xm)) # using offset argument xa2 <- ts(rnorm(10)) as.Date(time(xa2), offset = 2000)