interpolatePop: Interpolate between two population age distributions.

In timriffe/DemoTools: Standardize, Evaluate, and Adjust Demographic Data

Interpolate between two population age distributions.

Description

The interpolation is done by age (not cohort) using a linear or exponential function. This comes from the PAS spreadsheet called ADJINT.

Usage

interpolatePop(
  Pop1,
  Pop2,
  Date1,
  Date2,
  DesiredDate,
  method = "linear",
  roundoutput = FALSE
)

Arguments

Pop1	numeric. A vector of demographic counts by age at time 1 (earlier date).
Pop2	numeric. A vector of demographic counts by age at time 2 (later date).
Date1	date. The date corresponding to the population age distribution at time 1. See details for ways to express it.
Date2	date. The date corresponding to the population age distribution at time 2. See details for ways to express it.
DesiredDate	date. The desired date of the output population age distribution. See details for ways to express it.
method	string. The method to use for the interpolation, either "linear" or "exponential". Default "linear".
roundoutput	logical. Whether or not to return integers. Default FALSE.

Details

The age group structure of the output is the same as that of the input. Ideally, DesiredDate should be between the Date1 and Date2. Dates can be given in three ways 1) a Date class object, 2) an unambiguous character string in the format "YYYY-MM-DD", or 3) as a decimal date consisting in the year plus the fraction of the year passed as of the given date.

Value

A vector of the interpolated population for the requested date.

Author(s)

Sean Fennel

References

\insertRef

PASDemoTools

Examples

# YYYY-MM-DD dates as character
EarlyDate       <- "1980-04-07"
LaterDate       <- "1990-10-06"
DesiredDate     <- "1985-07-01"

interpolatePop(popA_earlier, popA_later, EarlyDate, LaterDate, DesiredDate)
interpolatePop(popA_earlier, popA_later, EarlyDate, LaterDate, DesiredDate, method = "exponential")
## Not run: 
plot(popA_earlier, t ='l', col='red',
    ylim = c(400,1220000),
    ylab = 'The counts', xlab = 'Age groups')

lines(interpolatePop(popA_earlier, popA_later, EarlyDate, LaterDate, DesiredDate),
     t = 'l', col='black')

lines(popA_later,
     t = 'l', col='blue')

legend(12,1000000,
      legend = c('Pop in 1980-04-07',
                 'Pop in 1985-07-01',
                 'Pop in 1990-10-06'),
      col=c('red','black','blue'),
      lty = 1)

## End(Not run)

timriffe/DemoTools documentation built on Jan. 28, 2024, 5:13 a.m.