as.tess: Convert Data To Tessellation

Description

Converts data specifying a tessellation, in any of several formats, into an object of class "tess".

Usage

as.tess(X)
 ## S3 method for class 'tess':
as.tess(X)
 ## S3 method for class 'im':
as.tess(X)
 ## S3 method for class 'owin':
as.tess(X)
 ## S3 method for class 'quadratcount':
as.tess(X)
 ## S3 method for class 'quadrattest':
as.tess(X)
 ## S3 method for class 'list':
as.tess(X)

Arguments

Data to be converted to a tessellation.

Value

An object of class "tess" specifying a tessellation.

Details

A tessellation is a collection of disjoint spatial regions (called tiles) that fit together to form a larger spatial region. This command creates an object of class "tess" that represents a tessellation.

This function converts data in any of several formats into an object of class "tess" for use by the spatstat package. The argument X may be

an object of class"tess". The object will be stripped of any extraneous attributes and returned.
a pixel image (object of class"im") with pixel values that are logical or factor values. Each level of the factor will determine a tile of the tessellation.
a window (object of class"owin"). The result will be a tessellation consisting of a single tile.
a set of quadrat counts (object of class"quadratcount") returned by the commandquadratcount. The quadrats used to generate the counts will be extracted and returned as a tessellation.
a quadrat test (object of class"quadrattest") returned by the commandquadrat.test. The quadrats used to perform the test will be extracted and returned as a tessellation.
a list of windows (objects of class"owin") giving the tiles of the tessellation.

The function as.tess is generic, with methods for various classes, as listed above.

Examples

Run this code

# pixel image
 v <- as.im(function(x,y){factor(round(5 * (x^2 + y^2)))}, W=owin())
 levels(v) <- letters[seq(length(levels(v)))]
 as.tess(v)
 # quadrat counts
 data(nztrees)
 qNZ <- quadratcount(nztrees, nx=4, ny=3)
 as.tess(qNZ)