Three-Parameter Log-Logistic Model with log(ED50) and Lower Limit at 0

A three-parameter log-logistic model where the lower limit is fixed at 0. The estimated parameters are the slope b, the upper limit d, and the log(ED50) e.

Usage

LL2.3(fixed = c(NA, NA, NA), names = c("b", "d", "e"), ...)

Arguments

fixed

numeric vector of length 3. Specifies which parameters are fixed and at what value. Use NA for parameters that should be estimated.

names

character vector of length 3 giving the names of the parameters b, d, and e.

...

additional arguments passed to llogistic2.

Value

A list of class "llogistic" with the nonlinear function, self-starter, and related components.

See also

llogistic2, LL2.2, LL2.4

Examples

ryegrass.m1 <- drm(rootl ~ conc, data = ryegrass, fct = LL2.3())