| l5 {drc} | R Documentation |
'l5' provides the five-parameter logistic function, self starter function and names of the parameters.
l5(fixed = c(NA, NA, NA, NA, NA), names = c("b", "c", "d", "e", "f"), useDer = FALSE)
fixed |
numeric vector. Specifies which parameters are fixed and at what value they are fixed. NAs for parameter that are not fixed. |
names |
a vector of character strings giving the names of the parameters. The default is reasonable. |
useDer |
logical. If TRUE derivatives are supplied, otherwise they are not supplied. Not implemented! |
The five-parameter logistic function is given by the expression
f(x) = c + frac{d-c}{(1+exp(b(log(x)-log(e))))^f}
The function is asymmetric for f different from 1.
See logistic.
This function is for use with the function multdrc.
Christian Ritz
Finney, D. J. (1979) Bioassay and the Practise of Statistical Inference, Int. Statist. Rev., 47, 1–12.
Related functions are l4 and l3.
model1 <- multdrc(FA, fct=l5()) summary(model1) rm(model1)