I think I am doing something wrong when I try to bootstrap R square
obtained from lm. My code is included below. No matter how many times I
run the simulation, I always get exactly the same result, the bias and
std.error are always zero. I would think that these values should be
non-zero. I would appreciate any suggestions as to what I am doing
wrong, or perhaps what I fail to understand.
R 2.1.0 Patched Win 2k.
Thanks,
John
 
 
>detefun3<-function (d,w)
summary(lm(d$sg120~d$fg120adj,data=d))$r.square
> boot(delete,deletefun3,R=200)
 
ORDINARY NONPARAMETRIC BOOTSTRAP

Call:
boot(data = delete, statistic = deletefun3, R = 200)

Bootstrap Statistics :
     original  bias    std. error
t1* 0.3028048       0           0
> 
 
John Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
Baltimore VA Medical Center GRECC and
University of Maryland School of Medicine Claude Pepper OAIC
 
University of Maryland School of Medicine
Division of Gerontology
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
 
410-605-7119 
- NOTE NEW EMAIL ADDRESS:
jsorkin@grecc.umaryland.edu

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