index {zoo} | R Documentation |
Generic functions for extracting the index of an object and replacing it.
index(x, ...)
index(x) <- value
x |
an object. |
... |
further arguments passed to methods. |
value |
an ordered vector of the same length
as the |
index
is a generic function for extracting the index
of objects, currently it has a default method and a method
for zoo
objects which is the same as the
time
method for zoo
objects.
Another pair of generic functions provides replacing
the index
or time
attribute.
Methods are available for "zoo"
objects only, see examples below.
The start and end of the index/time can be queried by using
the methods of start
and end
.
suppressWarnings(RNGversion("3.5.0"))
set.seed(1)
x.date <- as.Date(paste(2003, 2, c(1, 3, 7, 9, 14), sep = "-"))
x <- zoo(rnorm(5), x.date)
## query index/time of a zoo object
index(x)
time(x)
## change class of index from Date to POSIXct
## relative to current time zone
x
index(x) <- as.POSIXct(format(time(x)),tz="")
x
## replace index/time of a zoo object
index(x) <- 1:5
x
time(x) <- 6:10
x
## query start and end of a zoo object
start(x)
end(x)
## query index of a usual matrix
xm <- matrix(rnorm(10), ncol = 2)
index(xm)