spatstat.geom (version 2.0-1)

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 tess
as.tess(X)
 # S3 method for im
as.tess(X)
 # S3 method for owin
as.tess(X)
 # S3 method for quadratcount
as.tess(X)
 # S3 method for list
as.tess(X)

Arguments

X

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 command quadratcount. 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 command quadrat.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.

See Also

tess

Examples

# NOT RUN {
 # 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)
# }