collapseOrigDest {dembase}R Documentation

Convert data on movements into a less detailed format.

Description

Convert data on movements classifed by state of origin and state of destination into a less detailed format. The choices of format are

"out"

Total outward moves from each state

"in"

Total inward moves to each state

"pool"

"out" and "in"

"net"

"in" minus "out"

Usage

collapseOrigDest(
  object,
  base = NULL,
  to = c("net", "pool", "in", "out"),
  weights,
  omitted = ifelse(methods::is(object, "Counts"), 0L, NA_integer_),
  ...
)

## S4 method for signature 'Counts,ANY,ANY,missing'
collapseOrigDest(
  object,
  base = NULL,
  to = c("net", "pool", "in", "out"),
  omitted = ifelse(methods::is(object, "Counts"), 0L, NA_integer_)
)

## S4 method for signature 'Values,ANY,ANY,ANY'
collapseOrigDest(
  object,
  base = NULL,
  to = c("net", "pool", "in", "out"),
  weights,
  omitted = ifelse(methods::is(object, "Counts"), 0L, NA_integer_)
)

Arguments

object

Object of class DemographicArray.

base

Character vector giving the "base names" for the origin-destination pairs. If base is omitted, the base names from all dimensions with dimtype "origin" and "destination" are used.

to

The new format(s): "net" (the default), "out", and "in".

weights

Object of class Counts providing the weights to be used. Required if object has class Values, and prohibited if it has class Counts.

omitted

Value to be used for omitted origin-destination or parent-child combinations. Defaults to 0 when object has class Counts and NA otherwise.

...

Not currently used.

Details

collapseOrigDest calls function alignPair before collapsing cells. Argument omitted is passed to alignPair.

Value

If object has class linkS4class{Counts} and to is "net", then the return value has class Net. If object has class linkS4class{Counts} and' to is "pool", then the return value has class Pool. Otherwise the return value has the same class as object.

Warning

If ans is the result of applying collapseOrigDest to x, then sum(ans) does not necessarily equal sum(x). For instance, sum(collapseOrigDest(x, to = "net")) is always 0.

References

Wilson, T. and Bell, M. (2004) Comparative empirical evaluations of internal migration models in subnational population projections. Journal of Population Research. 21(2): 127-160.

See Also

alignPair collapseCategories, collapseIntervals, collapseIterations, collapseOrigDest, collapseDimension, dimtypes, dimscales

Examples

library(demdata)
mig <- Counts(nz.mig)
collapseOrigDest(mig, base = "island", to = "net")

## base defaults to all origin-destination base names,
## and 'to' defaults to "net"
collapseOrigDest(mig)

## multiple formats, distinguished by dimension "direction"
collapseOrigDest(mig, to = "pool")
collapseOrigDest(mig, to = "net")
collapseOrigDest(mig, to = "out")

## different representations imply different totals
sum(mig)
sum(collapseOrigDest(mig, to = "net"))
sum(collapseOrigDest(mig, to = "pool"))

x <- Counts(array(1:4,
                  dim = c(2, 2),
                  dimnames = list(region_orig = c("a", "b"),
                  region_dest = c("c", "b"))))
x
## extra categories are added to region_orig and
## region_dest via 'alignPair' before collapsing
collapseOrigDest(x, to = "pool")
[Package dembase version 0.0.0.119 Index]