Calculate Keyfitz entropy for a stage-based matrix population model

Computes Keyfitz entropy from the U submatrix of a stage-based (Lefkovitch) matrix population model.

entropy_k_stage(Umat, init_distrib = NULL, max_age = NULL, n_is_maxage = FALSE)

Arguments

Umat

A square numeric matrix representing the U submatrix of a stage-based (Lefkovitch) matrix population model.

init_distrib

The initial cohort distribution across stages. This should sum to 1. If it does not sum to 1, the function rescales it to 1. Defaults to an equal distribution across stages.

max_age

The upper age, in units of the projection interval. Defaults to 1000 if no information is provided.

n_is_maxage

If TRUE, survival p_n is set to zero. Defaults to FALSE.

Value

Returns a single numeric value representing the Keyfitz entropy for the given matrix. This value quantifies the dispersion of age at death.

References

Keyfitz, N. 1977. Applied Mathematical Demography. New York: Wiley.

See also

Other life history traits: entropy_d(), entropy_k_age(), entropy_k(), gen_time(), life_elas(), life_expect_mean(), longevity(), net_repro_rate(), repro_maturity, shape_rep(), shape_surv()

Author

Stefano Giaimo <giaimo@evolbio.mpg.de>

Owen Jones <jones@biology.sdu.dk>

Examples

data(mpm1)

entropy_k_stage(mpm1$matU)
#> [1] 1.131567