index

Extracting/Replacing the Index of Objects

Generic functions for extracting the index of an object and replacing it.

Usage

index(x, …)
index(x) <- value

Details

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.

See Also

time, zoo

Aliases

• index
• index.default
• index.zoo
• index.ts
• time.zoo
• index<-
• index<-.zoo
• time<-
• time<-.zoo
• start.zoo
• end.zoo

Examples

# NOT RUN {
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)
# }