Gets and sets the "parnames" attribute on a
negative log-likelihood function
Usage
parnames(obj)
parnames(obj) <- value
Arguments
obj
a negative log-likelihood function
value
a character vector of parameter names
Details
The parnames attribute is used by mle2()
when the negative log-likelihood function takes a parameter
vector, rather than a list of parameters; this allows
users to use the same objective function for optim()
and mle2()
Value
Returns the parnames attribute (a character vector of
parameter names) or sets it.
Author(s)
Ben Bolker
Examples
x <- 1:5
set.seed(1001)
y <- rbinom(5,prob=x/(1+x),size=10)
mfun <- function(p) {
a <- p[1]
b <- p[2]
-sum(dbinom(y,prob=a*x/(b+x),size=10,log=TRUE))
}
optim(fn=mfun,par=c(1,1))
parnames(mfun) <- c("a","b")
mle2(minuslogl=mfun,start=c(a=1,b=1),method="Nelder-Mead")