Extract.fasp {spatstat.explore}

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 \times 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 [e-mail], Rolf Turner [e-mail] and Ege Rubak [e-mail]

See Also

fasp.object

Examples

 online <- interactive()
 # Lansing woods data - multitype points with 6 types
 X <- lansing

 if(!online) {
   # subsample data (from 2251 to 450 points) to shorten check time
   X <- X[c(FALSE,FALSE,FALSE,FALSE,TRUE)]
 }

 a <- alltypes(X, 'K')

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