R: Extract or replace a slab from a demographic array.

slab {dembase}

R Documentation

Extract or replace a slab from a demographic array.

Description

Extract a slab length(elements) thick from object, perpendicular to the dimension specified by dimension, or replace the current values of the slab with new values

Usage

slab(object, dimension, elements, drop = TRUE)

slab(object, dimension, elements, drop = TRUE) <- value

## S4 method for signature 'Component'
slab(object, dimension, elements, drop = TRUE)

## S4 method for signature 'Births'
slab(object, dimension, elements, drop = TRUE)

## S4 method for signature 'InternalMovementsPool'
slab(object, dimension, elements, drop = TRUE)

## S4 method for signature 'InternalMovementsNet'
slab(object, dimension, elements, drop = TRUE)

## S4 method for signature 'DemographicArray'
slab(object, dimension, elements, drop = TRUE)

## S4 replacement method for signature 'DemographicArray'
slab(object, dimension, elements, drop = TRUE) <- value

Arguments

`object`	Object of class `DemographicArray`.
`dimension`	Name or index of dimension.
`elements`	Labels or indices of elements with in `dimension`.
`drop`	`TRUE`, `FALSE`, or the word `"dimension"` (possibly abbreviated). Defaults to `TRUE`. result.
`value`	An numeric vector, or an object that can be coerced to a numeric vector.

Details

slab is designed for programming, in situations where the dimension of an object is not fixed in advance (which makes [ inconvenient). In interactive use, subarray may be a better choice, as it is clearer and more flexible.

When drop is set to TRUE or FALSE, it works exactly like the drop argument in standard R extract functions (eg Extract. If drop is TRUE, then all length-one dimensions in the return value are removed; if drop is FALSE, then all length-one dimensions are preserved. slab, however, has a third option, the word "dimension". In this case the only dimension eligible for dropping if it is length one is the dimension specified by the dimension argument. See below for an example. Note that the word "dimension" can be abbreviated.

The replacement method ignores any attributes attached to code such as dimensions or dimnames. In particular, if value is a DemographicArray object, any metadata is ignored.

Examples

library(demdata)
x <- Values(VADeaths2)
x
slab(x, dimension = "age", elements = 1:3)
slab(x, dimension = 1, elements = 1:3)
slab(x, dimension = "age", elements = c("50-54", "70-74"))
slab(x, dimension = "sex", elements = 1)
slab(x, dimension = "sex", elements = 1, drop = FALSE)

slab(x, dimension = "sex", elements = "Male") <- 999
x
slab(x, dimension = "age", elements = "50-54") <- 1:4
x

x1 <- slab(x, dimension = "age", elements = 1, drop = FALSE)
x1
## drop length-one "sex" and "age" dimensions:
slab(x1, dimension = "sex", elements = "Male", drop = TRUE)
## don't drop any length-one dimensions:
slab(x1, dimension = "sex", elements = "Male", drop = FALSE)
## only drop the length-one "sex" dimension:
slab(x1, dimension = "sex", elements = "Male", drop = "dimension")
## abbreviate "dimension"
slab(x1, dimension = "sex", elements = "Male", drop = "dim")