sp_rate0: Simple Projection Model Based on Population Growth Rates
In gjabel/demoproj: Demographic Projection Models

Description Usage Arguments Value Examples

A simple projection model based on population growth rates,

N_{t} = N_{t} \times (1 + r_{t,t+1})

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sp_rate0(n = NULL, N0 = NULL, r = NULL)

sp_rate(n = NULL, N0 = NULL, r = NULL)

n

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

N0

Numeric value for the initial total population size.

r

Numeric value for the population growth rate in each projection period.

If sp_rate0 is used a single value is required.

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

A vector of length n + 1 containing the initial total population size (N0) and the projected total population sizes given r.

sp_rate0 produces population projections based strictly on constant future rates.

sp_rate produces population projections based non-constant future rates.

# constant future assumptions
sp_rate0(n = 20, N0 = 100, r = 0.05)

# non-constant future assumptions
rr <- rnorm(n = 20, mean = 0.05, sd = 0.01)
sp_rate(n = 20, N0 = 100, r = rr)