sp_demo0: Simple Projection Model Based on Crude Demographic Rates
In gjabel/demoproj: Demographic Projection Models

Description Usage Arguments Value Examples

A simple projection model based on crude demographic rates,

N_{t+1} = N_t + \times (1 + b_{t,t+1} - d_{t,t+1} + m_{t,t+1})

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sp_demo0(n = NULL, N0 = NULL, b = NULL, d = NULL, m = NULL)

sp_demo(n = NULL, N0 = NULL, b = NULL, d = NULL, m = NULL)

n

Numeric value for the number of projection periods to run the model.

N0

Numeric value for the initial total population size.

b, d, m

Numeric value for the crude birth, death and net migration rate in each projection period.

If sp_demo0 is used a single value is required.

If sp_demo is used a vector of period specific rates is required. If a single rate values are passed to sp_demo a vector based on constant assumptions in all future rates will be constructed.

A vector of length n + 1 containing the intial total population size (N0) and the projected total population sizes given b, d and m.

sp_demo0 produces population projections based strictly on constant future rates.

sp_demo produces population projections based non-constant future rates.

# constant future assumptions
sp_demo0(n = 20, N0 = 100, b = 0.04, d = 0.02, m = 0.03)

# non-constant future assumptions
dd <- rnorm(n = 20, mean = 0.02, sd = 0.001)
mm <- rnorm(n = 20, mean = 0.03, sd = 0.01)
sp_demo(n = 20, N0 = 100, b = 0.04, d = dd, m = mm)