split.msr: Divide a Measure into Parts

In spatstat.core: Core Functionality of the 'spatstat' Family

Divide a Measure into Parts

Description

Decomposes a measure into components, each component being a measure.

Usage

  ## S3 method for class 'msr'
split(x, f, drop = FALSE, ...)

Arguments

x	Measure (object of class "msr") to be decomposed.
f	Factor or tessellation determining the decomposition. Argument passed to split.ppp. See Details.
drop	Logical value indicating whether empty components should be retained in the list (drop=FALSE, the default) or deleted (drop=TRUE).
...	Ignored.

Details

An object of class "msr" represents a signed (i.e. real-valued) or vector-valued measure in the spatstat package. See msr for explanation.

This function is a method for the generic split. It divides the measure x into components, each of which is a measure.

A measure x is represented in spatstat by a finite set of sample points with values attached to them. The function split.msr divides this pattern of sample points into several sub-patterns of points using split.ppp. For each sub-pattern, the values attached to these points are extracted from x, and these values and sample points determine a measure, which is a component or piece of the original x.

The argument f can be missing, if the sample points of x are multitype points. In this case, x represents a measure associated with marked spatial locations, and the command split(x) separates x into a list of component measures, one for each possible mark.

Otherwise the argument f is passed to split.ppp. It should be either a factor (of length equal to the number of sample points of x) or a tessellation (object of class "tess" representing a division of space into tiles) as documented under split.ppp.

Value

A list, each of whose entries is a measure (object of class "msr").

Author(s)

\spatstatAuthors

See Also

msr, [.msr, with.msr

Examples

  ## split by tessellation
  a <- residuals(ppm(cells ~ x))
  aa <- split(a, dirichlet(runifpoint(4)))
  aa
  sapply(aa, integral)

  ## split by type of point
  b <- residuals(ppm(amacrine ~ marks + x))
  bb <- split(b)
  bb

spatstat.core documentation built on May 18, 2022, 9:05 a.m.