# Window

##### Extract or Change the Window of a Spatial Object

Given a spatial object (such as a point pattern or pixel image) in two dimensions, these functions extract or change the window in which the object is defined.

##### Usage

`Window(X, ...)` Window(X, ...) <- value

## S3 method for class 'ppp':
Window(X, \dots)

## S3 method for class 'ppp':
Window(X, \dots) <- value

## S3 method for class 'psp':
Window(X, \dots)

## S3 method for class 'psp':
Window(X, \dots) <- value

## S3 method for class 'im':
Window(X, \dots)

## S3 method for class 'im':
Window(X, \dots) <- value

##### Arguments

- X
- A spatial object such as a point pattern, line segment pattern or pixel image.
- ...
- Extra arguments. They are ignored by all the methods listed here.
- value
- Another window (object of class
`"owin"`

) to be used as the window for`X`

.

##### Details

The functions `Window`

and `Window<-`

are generic.

`Window(X)`

extracts the spatial window in which `X`

is
defined.

`Window(X) <- W`

changes the window in which `X`

is defined
to the new window `W`

, and *discards any data outside* `W`

.
In particular:

- If
`X`

is a point pattern (object of class`"ppp"`

) then`Window(X) <- W`

discards any points of`X`

which fall outside`W`

. - If
`X`

is a line segment pattern (object of class`"psp"`

) then`Window(X) <- W`

clips the segments of`X`

to the boundaries of`W`

. - If
`X`

is a pixel image (object of class`"im"`

) then`Window(X) <- W`

has the effect that pixels lying outside`W`

are retained but their pixel values are set to`NA`

.

Many other classes of spatial object have a method
for `Window`

, but not `Window<-`

.
See `Window.ppm`

.

##### Value

- The result of
`Window`

is a window (object of class`"owin"`

).The result of

`Window<-`

is the updated object`X`

, of the same class as`X`

.

##### See Also

##### Examples

```
## point patterns
Window(cells)
X <- demopat
Window(X)
Window(X) <- as.rectangle(Window(X))
## line segment patterns
X <- psp(runif(10), runif(10), runif(10), runif(10), window=owin())
Window(X)
Window(X) <- square(0.5)
## images
Z <- setcov(owin())
Window(Z)
Window(Z) <- square(0.5)
```

*Documentation reproduced from package spatstat, version 1.41-1, License: GPL (>= 2)*