This method could be useful whenever a reasonable standard is available. At present the standard must be supplied by the user.

OPAG_simple(Pop, Age, OAnow = max(Age), StPop, StAge, OAnew = max(StAge))

## Arguments

Pop numeric vector of population counts integer vector of single age lower bounds integer. The lower age bound above which counts will be redistributed numeric vector of standard population counts integer vector of single age lower bounds for the standard population integer. The desired new open age, must be no higher than max(StAge).

## Details

In this implementation both the original population counts and the standard must be in single ages.

## References

United States Census Bureau (2017). “Population Analysis System (PAS) Software.” https://www.census.gov/data/software/pas.html, https://www.census.gov/data/software/pas.html.

## Examples

 Pop        <- c(38129,38382,38824,39275,39500,37304,35152,
34061,33911,32875,31599,30376,29822,29691,28765,
28695,28917,28203,29209,30316,29062,26977,26577,
27727,28599,30513,31774,32347,34093,33736,32085,
30807,28279,26873,25612,23503,22207,21388,20122,
18014,15626,15006,14158,11195,7931,7640,9053,
13276,17226,18918,17697,18424,17723,16706,14410,
13342,14787,15183,15727,16045,14777,14267,13102,
10866,9311,6933,5030,3785,3551,2848,3080,
2874,2368,2681,3165,3010,3009,2721,2705,
2492,2244,1971,1644,1565,1307,5027)
Age        <- 0:85
# standard pop taken from ages 55+
StPop      <- c(6258,6177,6089,5995,5894,5787,5672,5552,
5423,5286,5140,4985,4824,4652,4477,4293,
4107,3912,3712,3502,3282,3055,2823,2591,
2360,2138,1921,1710,1502,1297,1098,910,
741,592,463,353,265,192,137,95,
63,42,26,17,9,13)

StAge      <- 55:100

PopExtended <- OPAG_simple(
Pop = Pop,
Age = Age,
StPop = StPop,
StAge = StAge)

if (FALSE) {
plot(Age, Pop, type = 'l',xlim=c(80,100),ylim=c(0,1e4))
lines(0:100, PopExtended, col = "red", lty = 2)
}
stopifnot((sum(PopExtended[86:101]) - Pop[86]) == 0)