growthmodels (version 1.3.1)

gompertz: Gompertz growth model

Description

Computes the Gompertz growth model and its inverse $$ y(t) = \alpha exp(-\beta exp(-k^t))$$

Usage

gompertz(t, alpha, beta, k)
gompertz.inverse(x, alpha, beta, k)

Arguments

t

time

alpha

upper asymptote

beta

growth displacement

k

growth rate

x

size

Author

Daniel Rodriguez

References

D. Fekedulegn, M. Mac Siurtain, and J. Colbert, "Parameter estimation of nonlinear growth models in forestry," Silva Fennica, vol. 33, no. 4, pp. 327-336, 1999.

Examples

growth <- gompertz(0:10, 10, 0.5, 0.3)

# Calculate inverse function
time <- gompertz.inverse(growth, 10, 0.5, 0.3)