Converts data specifying an observation window
in any of several formats, into an object of class `"owin"`

.

`as.owin(W, …, fatal=TRUE)` # S3 method for default
as.owin(W, …, fatal=TRUE)

# S3 method for owin
as.owin(W, …, fatal=TRUE)

# S3 method for ppp
as.owin(W, …, fatal=TRUE)

# S3 method for psp
as.owin(W, …, fatal=TRUE)

# S3 method for quad
as.owin(W, …, fatal=TRUE)

# S3 method for quadratcount
as.owin(W, …, fatal=TRUE)

# S3 method for tess
as.owin(W, …, fatal=TRUE)

# S3 method for im
as.owin(W, …, fatal=TRUE)

# S3 method for layered
as.owin(W, …, fatal=TRUE)

# S3 method for data.frame
as.owin(W, …, step, fatal=TRUE)

# S3 method for distfun
as.owin(W, …, fatal=TRUE)

# S3 method for nnfun
as.owin(W, …, fatal=TRUE)

# S3 method for funxy
as.owin(W, …, fatal=TRUE)

# S3 method for boxx
as.owin(W, …, fatal=TRUE)

W

Data specifying an observation window, in any of several formats
described under *Details* below.

fatal

Logical value determining what to do if the data cannot be converted to an observation window. See Details.

…

Ignored.

step

Optional. A single number, or numeric vector of length 2, giving the grid step lengths in the \(x\) and \(y\) directions.

An object of class `"owin"`

(see `owin.object`

)
specifying an observation window.

The class `"owin"`

is a way of specifying the observation window
for a point pattern. See `owin.object`

for an overview.

The generic function `as.owin`

converts data in any of several formats
into an object of class `"owin"`

for use by the spatstat
package. The function `as.owin`

is generic, with methods
for different classes of objects, and a default method.

The argument `W`

may be

an object of class

`"owin"`

a structure with entries

`xrange`

,`yrange`

specifying the \(x\) and \(y\) dimensions of a rectanglea structure with entries named

`xmin`

,`xmax`

,`ymin`

,`ymax`

(in any order) specifying the \(x\) and \(y\) dimensions of a rectangle. This will accept objects of class`bbox`

in the`sf`

package.a numeric vector of length 4 (interpreted as

`(xmin, xmax, ymin, ymax)`

in that order) specifying the \(x\) and \(y\) dimensions of a rectanglea structure with entries named

`xl`

,`xu`

,`yl`

,`yu`

(in any order) specifying the \(x\) and \(y\) dimensions of a rectangle as`(xmin, xmax) = (xl, xu)`

and`(ymin, ymax) = (yl, yu)`

. This will accept objects of class`spp`

used in the Venables and Ripley spatial package.an object of class

`"ppp"`

representing a point pattern. In this case, the object's`window`

structure will be extracted.an object of class

`"psp"`

representing a line segment pattern. In this case, the object's`window`

structure will be extracted.an object of class

`"tess"`

representing a tessellation. In this case, the object's`window`

structure will be extracted.an object of class

`"quad"`

representing a quadrature scheme. In this case, the window of the`data`

component will be extracted.an object of class

`"im"`

representing a pixel image. In this case, a window of type`"mask"`

will be returned, with the same pixel raster coordinates as the image. An image pixel value of`NA`

, signifying that the pixel lies outside the window, is transformed into the logical value`FALSE`

, which is the corresponding convention for window masks.A

`data.frame`

with exactly three columns. Each row of the data frame corresponds to one pixel. Each row contains the \(x\) and \(y\) coordinates of a pixel, and a logical value indicating whether the pixel lies inside the window.A

`data.frame`

with exactly two columns. Each row of the data frame contains the \(x\) and \(y\) coordinates of a pixel that lies inside the window.an object of class

`"distfun"`

,`"nnfun"`

or`"funxy"`

representing a function of spatial location, defined on a spatial domain. The spatial domain of the function will be extracted.an object of class

`"layered"`

representing a list of spatial objects. See`layered`

. In this case,`as.owin`

will be applied to each of the objects in the list, and the union of these windows will be returned.an object of class

`"SpatialPolygon"`

,`"SpatialPolygons"`

or`"SpatialPolygonsDataFrame"`

. To handle these data types,**the package**maptools**must be loaded**, because it provides the methods for`as.owin`

for these classes. For full details, see`vignette('shapefiles')`

.

If the argument `W`

is not in one of these formats
and cannot be converted to a window, then an error will
be generated (if `fatal=TRUE`

) or a value of `NULL`

will be returned (if `fatal=FALSE`

).

When `W`

is a data frame, the argument `step`

can be used to specify the pixel grid spacing; otherwise, the spacing
will be guessed from the data.

Additional methods for `as.owin`

are provided
in the maptools package:
`as.owin.SpatialPolygon`

,
`as.owin.SpatialPolygons`

,
`as.owin.SpatialPolygonsDataFrame`

.

# NOT RUN { w <- as.owin(c(0,1,0,1)) w <- as.owin(list(xrange=c(0,5),yrange=c(0,10))) # point pattern data(demopat) w <- as.owin(demopat) # image Z <- as.im(function(x,y) { x + 3}, unit.square()) w <- as.owin(Z) # Venables & Ripley 'spatial' package spatialpath <- system.file(package="spatial") if(nchar(spatialpath) > 0) { require(spatial) towns <- ppinit("towns.dat") w <- as.owin(towns) detach(package:spatial) } # }