R: Convert Data To Tessellation

as.tess {spatstat.geom} | R Documentation

## 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 'list'
    as.tess(X)

### Arguments

`X` | Data to be converted to 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.

### Value

An object of class `"tess"` specifying a tessellation.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

and Rolf Turner r.turner@auckland.ac.nz

### See Also

`tess`

### Examples

     # 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)

[Package spatstat.geom version 2.3-2 Index]