library(RTMB)
dat <- read.table("bh.dat", header=TRUE)
par <- list(loga=0, logb=0, logsigma=0)

nll<-function(par){
  getAll(par, dat)
  sigma <- exp(logsigma)
  pred <- loga+log(ssb)-log(1+exp(logb)*ssb)
  nll <- -sum(dnorm(logR,pred,sigma,TRUE))
  return(nll)
}

obj <- MakeADFun(nll, par, silent=TRUE)
opt <- nlminb(obj$par, obj$fn, obj$gr)
print(opt$par)


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