lr.loglike <-
function(betas,Y,X,intercept=TRUE){
if(!intercept){
lp<-X %*% betas
}else{
lp<-cbind(rep(1,length(Y)),X) %*% betas
}
pv<-expit(lp)
return(sum(dbinom(Y,1,pv,log=T)))
}