spatstat.geom: Window – R documentation

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Window

Extract or Change the Window of a Spatial Object

Description

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, ...)

   ## S3 replacement method for class 'ppp'
Window(X, ...) <- value

   ## S3 method for class 'psp'
Window(X, ...)

   ## S3 replacement method for class 'psp'
Window(X, ...) <- value

   ## S3 method for class 'im'
Window(X, ...)

   ## S3 replacement method for class 'im'
Window(X, ...) <- 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.

Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.

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)

spatstat.geom

Geometrical Functionality of the 'spatstat' Family

v2.1-0

GPL (>= 2)

Authors

Adrian Baddeley [aut, cre], Rolf Turner [aut], Ege Rubak [aut], Tilman Davies [ctb], Ute Hahn [ctb], Abdollah Jalilian [ctb], Sebastian Meyer [ctb], Suman Rakshit [ctb], Dominic Schuhmacher [ctb], Rasmus Waagepetersen [ctb]

Initial release

2021-04-15