growthmodels (version 1.3.1)

chapmanRichards: Chapman-Richards growth model

Description

Computes the Chapman-Richards growth model and its inverse $$ y(t) = \alpha (1 - \beta exp(-k t)^{1/(1-m)}) $$

Usage

chapmanRichards(t, alpha, beta, k, m)
chapmanRichards.inverse(x, alpha, beta, k, m)

Arguments

t

time

alpha

upper asymptote

beta

growth range

k

growth rate

m

slope of growth

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 <- chapmanRichards(0:10, 10, 0.5, 0.3, 0.5)

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