R: Extract Subset of Function Array

Extract.fasp {spatstat.core} | R Documentation

## Extract Subset of Function Array

### Description

Extract a subset of a function array (an object of class `"fasp"`).

### Usage

      ## S3 method for class 'fasp'
    x[I, J, drop=TRUE,...]

### Arguments

`x` | A function array. An object of class `"fasp"`.
`I` | any valid expression for a subset of the row indices of the array.
`J` | any valid expression for a subset of the column indices of the array.
`drop` | Logical. When the selected subset consists of only one cell of the array, if `drop=FALSE` the result is still returned as a 1 * 1 array of functions (class `"fasp"`) while if `drop=TRUE` it is returned as a function (class `"fv"`).
`...` | Ignored.

### Details

A function array can be regarded as a matrix whose entries are functions. See `fasp.object` for an explanation of function arrays.

This routine extracts a sub-array according to the usual conventions for matrix indexing.

### Value

A function array (of class `"fasp"`). Exceptionally, if the array has only one cell, and if `drop=TRUE`, then the result is a function value table (class `"fv"`).

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk

### See Also

`fasp.object`

### Examples

     # Lansing woods data - multitype points with 6 types
     a <- alltypes(lansing, 'K')

     # extract first three marks only
     b <- a[1:3,1:3]
     if(interactive()) {plot(b)}
     # subset of array pertaining to hickories
     h <- a["hickory", ]
     if(interactive()) {plot(h)}

[Package spatstat.core version 2.3-1 Index]