rje (version 1.9)

subtable: Subset an array

Description

More flexible calls of [ on an array.

Usage

subarray(x, levels, drop = TRUE)
subtable(x, variables, levels, drop = TRUE)
`subarray<-`(x, levels, value)
`subtable<-`(x, variables, levels, value)

Arguments

x

An array.

variables

An integer vector containing the dimensions of x to subset.

levels

A list or vector containing values to retain.

drop

Logical indicating whether dimensions with only 1 retained should be dropped. Defaults to TRUE.

value

Value to assign to entries in table.

Value

Returns an array of dimension sapply(value, length) if drop=TRUE, otherwise specified dimensions of size 1 are dropped. Dimensions which are unspecified in subtable are never dropped.

Details

Essentially just allows more flexible calls of [ on an array.

subarray requires the values for each dimension should be specified, so for a \(2 \times 2 \times 2\) array x, subarray(x, list(1,2,1:2)) is just x[1,2,1:2].

subtable allows unspecified dimensions to be retained automatically. Thus, for example subtable(x, c(2,3), list(1, 1:2)) is x[,1,1:2].

See Also

Extract

Examples

# NOT RUN {
x = array(1:8, rep(2,3))
subarray(x, c(2,1,2)) == x[2,1,2]

x[2,1:2,2,drop=FALSE]
subarray(x, list(2,1:2,2), drop=FALSE)

subtable(x, c(2,3), list(1, 1:2))
# }