Returns a population of individuals alive.
# S3 method for class 'population'
population_alive(object, t, a1 = 0, a2 = Inf, ...)
Arguments
- object
A population data frame containing at least a column birth and death.
- t
A numeric indicating the time.
- a1
0 by default. All individuals of age over a1 at t are selected.
- a2
Inf by default. All individuals of age below a2 at t are selected.
- ...
Additional params.
Value
The function returns a population data frame containing all individuals alive at time t and of age in [a1,a2).