R: Convert Pixel Image from Numeric to Factor

cut.im {spatstat} | R Documentation

## Convert Pixel Image from Numeric to Factor

### Description

Transform the values of a pixel image from numeric values into a factor.

### Usage

      ## S3 method for class 'im'
    cut(x, ...)

### Arguments

`x` | A pixel image. An object of class `"im"`.
`...` | Arguments passed to `cut.default`. They determine the breakpoints for the mapping from numerical values to factor values. See `cut.default`.

### Details

This simple function applies the generic `cut` operation to the pixel values of the image `x`. The range of pixel values is divided into several intervals, and each interval is associated with a level of a factor. The result is another pixel image, with the same window and pixel grid as `x`, but with the numeric value of each pixel discretised by replacing it by the factor level.

This function is a convenient way to inspect an image and to obtain summary statistics. See the examples.

To select a subset of an image, use the subset operator `[.im` instead.

### Value

A pixel image (object of class `"im"`) with pixel values that are a factor. See `im.object`.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

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

### See Also

`cut`, `im.object`

### Examples

      # artificial image data
      Z <- setcov(square(1))

      Y <- cut(Z, 3)
      Y <- cut(Z, breaks=seq(0,1,length=5))

      # cut at the quartiles
      # (divides the image into 4 equal areas)
      Y <- cut(Z, quantile(Z))

[Package spatstat version 1.63-3 Index]