index {zoo} | R Documentation |

## Extracting/Replacing the Index of Objects

### Description

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

### Usage

index(x, ...)
index(x) <- value

### Arguments

`x` |
an object. |

`...` |
further arguments passed to methods. |

`value` |
an ordered vector of the same length
as the `"index"` attribute of `x` . |

### 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`

### Examples

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)

[Package

*zoo* version 1.0-5

Index]