as.owin {spatstat} | R Documentation |
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 class 'owin' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'ppp' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'ppm' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'psp' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'quad' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'tess' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'im' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'gpc.poly' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'data.frame' as.owin(W, ..., fatal=TRUE) ## S3 method for class 'distfun' as.owin(W, ..., fatal=TRUE) ## Default S3 method: as.owin(W, ..., fatal=TRUE)
W |
Data specifying an observation window, in any of several formats described under Details below. |
fatal |
Logical flag determining what to do if the data cannot be converted to an observation window. See Details. |
... |
Ignored. |
The class "owin"
is a way of specifying the observation window
for a point pattern. See owin.object
for an overview.
This function converts data in any of several formats
into an object of class "owin"
for use by the spatstat
package. The argument W
may be
an object of class "owin"
a structure with entries xrange
, yrange
specifying the
x and y dimensions of a rectangle
a four-element vector
(interpreted as (xmin, xmax, ymin, ymax)
)
specifying the x and y dimensions of a rectangle
a structure with entries xl
, xu
, yl
, yu
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
library.
an object of class "gpc.poly"
from the gpclib package,
representing a polygonal window.
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.
an object of class "ppm"
representing a fitted point process
model. In this case, as.owin
extracts the original point
pattern data to which the model was fitted, and returns the
observation window of this point pattern.
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.
an object of class "distfun"
representing a
distance function. The spatial domain of the function will be
extracted.
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
).
The function as.owin
is generic, with methods for
"owin"
,
"im"
and
"ppp"
as well as the default method.
An object of class "owin"
(see owin.object
)
specifying an observation window.
Adrian Baddeley Adrian.Baddeley@csiro.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner r.turner@auckland.ac.nz
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 require(spatial) towns <- ppinit("towns.dat") w <- as.owin(towns) detach(package:spatial)