# window

##### Time Windows

`window`

is a generic function which
extracts the subset of the object `x`

observed between the times `start`

and `end`

. If a
frequency is specified, the series is then re-sampled at the new
frequency.

- Keywords
- ts

##### Usage

```
window(x, …)
# S3 method for ts
window(x, …)
# S3 method for default
window(x, start = NULL, end = NULL,
frequency = NULL, deltat = NULL, extend = FALSE, …)
```window(x, …) <- value
# S3 method for ts
window(x, start, end, frequency, deltat, …) <- value

##### Arguments

- x
- a time-series (or other object if not replacing values).
- start
- the start time of the period of interest.
- end
- the end time of the period of interest.
- frequency, deltat
- the new frequency can be specified by either (or both if they are consistent).
- extend
- logical. If true, the
`start`

and`end`

values are allowed to extend the series. If false, attempts to extend the series give a warning and are ignored. - …
- further arguments passed to or from other methods.
- value
- replacement values.

##### Details

The start and end times can be specified as for `ts`

. If
there is no observation at the new `start`

or `end`

,
the immediately following (`start`

) or preceding (`end`

)
observation time is used. The replacement function has a method for `ts`

objects, and
is allowed to extend the series (with a warning). There is no default
method.

##### Value

The value depends on the method. `window.default`

will return a
vector or matrix with an appropriate `tsp`

attribute. `window.ts`

differs from `window.default`

only in
ensuring the result is a `ts`

object. If `extend = TRUE`

the series will be padded with `NA`

s if
needed.

##### References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
*The New S Language*.
Wadsworth & Brooks/Cole.

##### See Also

##### Examples

`library(stats)`

```
window(presidents, 1960, c(1969,4)) # values in the 1960's
window(presidents, deltat = 1) # All Qtr1s
window(presidents, start = c(1945,3), deltat = 1) # All Qtr3s
window(presidents, 1944, c(1979,2), extend = TRUE)
pres <- window(presidents, 1945, c(1949,4)) # values in the 1940's
window(pres, 1945.25, 1945.50) <- c(60, 70)
window(pres, 1944, 1944.75) <- 0 # will generate a warning
window(pres, c(1945,4), c(1949,4), frequency = 1) <- 85:89
pres
```

*Documentation reproduced from package stats, version 3.3.3, License: Part of R 3.3.3*