`panel11pt2.fn` <-
## R script for optimizing the nest survival model likelihood shown in 
## Panel 9.2 for the American redstart data. The model is a simple 
## constant + AGE effect model. Requires nestdata.list

function(){
expit<-function(x){
exp(x)/(1+exp(x))
}
nind<-nestdata.list$nind
first<-nestdata.list$first
last<-nestdata.list$last
last1<-nestdata.list$last1
AGE<-nestdata.list$AGE


lik0<-function(parms){
beta0<-parms[1]
beta1<-parms[2]
lik2<-rep(1,nind)
lik1<-rep(NA,nind)
for(i in 1:nind){
phi<- expit(   beta0 + beta1* (AGE[i,]-10)/5)
 lik1[i]<-sum(log(phi[(first[i]+1):last1[i]]))
if(last1[i]<last[i])
  lik2[i]<- log(1-prod( phi[ (last1[i]+1):last[i]]))
  }
-1*sum(lik1  + lik2)
}


tmp<-nlm(lik0,c(0,0),hessian=TRUE)

tmp









}