R: Test Whether A Point Pattern is Marked

is.marked.ppp {spatstat} | R Documentation

## Test Whether A Point Pattern is Marked

### Description

Tests whether a point pattern has “marks” attached to the points.

### Usage

      ## S3 method for class 'ppp'
    is.marked(X, na.action="warn", ...)

### Arguments

`X` | Point pattern (object of class `"ppp"`)
`na.action` | String indicating what to do if `NA` values are encountered amongst the marks. Options are `"warn"`, `"fatal"` and `"ignore"`.
`...` | Ignored.

### Details

“Marks” are observations attached to each point of a point pattern. For example the `longleaf` dataset contains the locations of trees, each tree being marked by its diameter; the `amacrine` dataset gives the locations of cells of two types (on/off) and the type of cell may be regarded as a mark attached to the location of the cell.

This function tests whether the point pattern `X` contains or involves marked points. It is a method for the generic function `is.marked`.

The argument `na.action` determines what action will be taken if the point pattern has a vector of marks but some or all of the marks are `NA`. Options are `"fatal"` to cause a fatal error; `"warn"` to issue a warning and then return `TRUE`; and `"ignore"` to take no action except returning `TRUE`.

### Value

Logical value, equal to `TRUE` if `X` is a marked point pattern.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

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

### See Also

`is.marked`, `is.marked.ppm`

### Examples

       data(cells)
       is.marked(cells)  #FALSE
       data(longleaf)
       is.marked(longleaf) #TRUE

[Package spatstat version 1.63-3 Index]