as.owin
From spatstat v1.18-4
by Adrian Baddeley
Convert Data To Class owin
Converts data specifying an observation window
in any of several formats, into an object of class "owin"
.
Usage
as.owin(W, ..., fatal=TRUE)
## S3 method for class 'owin':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'ppp':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'ppm':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'psp':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'quad':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'tess':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'im':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'gpc.poly':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'data.frame':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'distfun':
as.owin(W, \dots, fatal=TRUE)
## S3 method for class 'default':
as.owin(W, \dots, fatal=TRUE)
Arguments
- 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.
Details
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 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 classspp
used in the Venables and Ripleyspatial library. - an object of class
"gpc.poly"
from thegpclib package, representing a polygonal window. - an object of class
"ppp"
representing a point pattern. In this case, the object'swindow
structure will be extracted. - an object of class
"psp"
representing a line segment pattern. In this case, the object'swindow
structure will be extracted. - an object of class
"tess"
representing a tessellation. In this case, the object'swindow
structure will be extracted. - an object of class
"quad"
representing a quadrature scheme. In this case, the window of thedata
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 ofNA
, signifying that the pixel lies outside the window, is transformed into the logical valueFALSE
, 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.
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.
Value
- An object of class
"owin"
(seeowin.object
) specifying an observation window.
See Also
Examples
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)
Community examples
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