Calculate exposure from population counts.

Description

object typically has a dimension with dimtype time and dimscale "Points", and a dimension with dimtype "age" and dimscale "Intervals". The complete set of choices for age-time-cohort dimensions and dimscales is

Usage

exposure(object, triangles = FALSE, openTriangles = c("weighted", "standard"))

## S4 method for signature 'Counts'
exposure(object, triangles = FALSE, openTriangles = c("weighted", "standard"))

Arguments

Details

If triangles is TRUE, then exposure is calculated separately for lower and upper Lexis triangles. triangles can only by TRUE if object has dimensions with dimtype "time" and "age".

Argument openTriangles governs the way that the exposures for the final age group are calculated when the final age group is open (ie has no upper age limit) and triangles is TRUE. The sum of the exposures for the upper and lower triangles is unaffected. When openTriangles is "weighted", exposure for the upper triangle is twice as large as exposure for the lower triangle (reflecting the fact that the upper triangle includes multiple cohorts). When openTriangles is "standard" exposure is calculated the same way as it is for other age groups.

Value

An object of class Counts.

See Also

To calculate exposure for births, see exposureBirths To calculate exposure for origin-destination or parent-child arrays, see addPair

Examples

## prepare data
library(demdata)
popn <- demdata::nz.popn.reg
popn <- Counts(popn, dimscales = c(year = "Points"))
popn <- subarray(popn, year %in% c(1996, 2001, 2006, 2011, 2016))
popn <- collapseDimension(popn, dimension = "region")

## no triangles
exposure(popn)

## with triangles
exposure(popn, triangles = TRUE)

## with triangles, openTriangles is "standard"
exposure(popn, triangles = TRUE, openTriangles = "standard")


## cohort
popn <- Counts(array(4:1,
                     dim = c(1, 4),
                     dimnames = list(cohort = "2001-2005",
                                     age = c(0, 5, 10, 15))))
exposure(popn)