growth_logistic {popstudy}

Logistic growth

Description

Given two pivots and limits, estimates the growth assuming a logistic behavior.

Usage

growth_logistic(pivot_values, pivot_years, upper, lower, t)

Arguments

pivot_values

numeric. Reference values to estimate, like TFR for two specific years.

pivot_years

numeric. Reference years to estimate for both values in pivot_values.

upper

numeric. Upper asymptotic value.

lower

numeric. Lower asymptotic value.

t

numeric. Year to get logistic value.

Value

growth_logistic returns the logistic estimation for specified year.

Author(s)

Cesar Gamboa-Sanabria

References

Shryock HS, Siegel JS (2013). The Methods and Materials of Demography, Studies in Population. Elsevier Science. ISBN 9781483289106, https://books.google.co.cr/books?id=HVW0BQAAQBAJ.

See Also

growth_exp, growth_linear

Examples

# Given TFR values 3.32 and 2.85 for the years 1986 and 1991, respectively,
# estimate the TFR in 1987 assuming 1.5 as lower limit and 8 as upper limit.

growth_logistic(pivot_values = c(3.32, 2.85), pivot_years = c(1986, 1991),
upper = 8, lower=1.5, t=1987)