Five-parameter generalized logistic model — L.5 • drc

A five-parameter generalized logistic model (asymmetric when f != 1), given by $$f(x) = c + \frac{d - c}{(1 + \exp(b(x - e)))^f}$$

Usage

L.5(fixed = c(NA, NA, NA, NA, NA), names = c("b", "c", "d", "e", "f"), ...)

Arguments

fixed: numeric vector of length 5. Specifies which parameters are fixed and at what value they are fixed. NA indicates that the corresponding parameter is not fixed.
names: character vector of length 5 giving the names of the parameters (b, c, d, e, f). Default is c("b", "c", "d", "e", "f").
...: additional arguments passed to logistic.

Value

A list of class "Boltzmann" containing the nonlinear function, self starter function, and parameter names.

See also

logistic, L.3, L.4

Examples

ryegrass.m1 <- drm(rootl ~ conc, data = ryegrass, fct = L.5())