W1.3 {drc} | R Documentation |
'W1.3' provides the three-parameter Weibull function, self starter function and names of the parameters.
W1.3(fixed = c(NA, NA, NA), names = c("b", "d", "e")) W2.3(fixed = c(NA, NA, NA), names = c("b", "d", "e"))
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. |
The three-parameter Weibull model is given by the expression
f(x) = 0 + (d-0)exp(-exp(b(log(x)-e))).
The function is asymmetric about the inflection point, that is the parameter exp(e).
See weibull1
.
This function is for use with the function multdrc
.
Christian Ritz
Related functions are W1.4
and weibull1
.
## Fitting a three-parameter Weibull model model1 <- multdrc(ryegrass, fct = W1.3()) model1 rm(model1)