sp_net0: Simple Projection Model Based on Crude Demographic Rates and...
In gjabel/demoproj: Demographic Projection Models

Description Usage Arguments Value Examples

A simple projection model based on crude demographic rates and net migration counts,

N_{t+1} = ≤ft( N_t + \frac{M_{t,t+1}}{2} \right) \times (1 + b_{t,t+1} - d_{t,t+1}) + \frac{M_{t,t+1}}{2}

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sp_net0(n = NULL, N0 = NULL, b = NULL, d = NULL, M = NULL)

sp_net(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 and death rates and net migration counts in each projection period.

If sp_net0 is used a single value is required.

If sp_net is used a vector of period specific rates (and net migration counts) is required. If a single rate values (and net migration count) are passed to sp_net a vector based on constant assumptions in all future rates (and net migration counts) will be constructed.

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

sp_net0 produces population projections based stricly on constant future rates and counts.

sp_net produces population projections based non-constant future rates and counts.

# constant future assumptions
sp_net0(n = 20, N0 = 100, b = 0.04, d = 0.02, M = 3)

# non-constant future assumptions
bb <- rnorm(n = 20, mean = 0.04, sd = 0.001)
MM <- rnorm(n = 20, mean = 3)
sp_net(n = 20, N0 = 100, b = bb, d = 0.02, M = MM)