Message-ID: <20080907192819.8rhjzj6pwg44k4og@wm-imp-3.unl.edu>
Date: 2008-09-08T00:28:19Z
From: ctu at bigred.unl.edu
Subject: Help parametric boot
Hi R users
Is there any example for nonlinear parametric boot? I google it but I
can't find it. I am interested in the parameter estimators of a
nonlinear model. But I really don't know how to code it in the
"ran.gen" statement (data set from ?nls)
> fm1 <- nls(weight ~ Asym/(1+exp((xmid-Time)/scal)), data = ChickWeight,
+ start=c(Asym=337, xmid=16, scal=8))
> fm1.fun<-function(data){coef(update(fm1,data=data))}
> ran.sim<-function(data,mle){out<-rnorm(n=nrow(data,mle));out}
> fm1.boot<-boot(ChickWeight, statistic = fm1.fun, R=99, sim="parametric",
+ ran.gen=ran.sim, mle=coef(fm1))
Error in nrow(data, mle) :
unused argument(s) (c(337.605336871528, 16.0688379710354, 8.00747460385483))
Any suggestion would be very helpful.
many thanks in advance
Chunhao