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<font face="Courier, Courier" size=2>I'm trying to adapt some S-Plus
scripts to run in R (1.2.2, Windows). In one of these scripts, I've
bootstrapped the prediction success rate under the discriminant function
(lda). The bootstrap() functions are proprietary to S-Plus and
there aren't exact equivalents in R. The closest is Canty's library
boot based on the Davidson and Hinkley book. Unfortunately, I
haven't been able to map the commands I used in the bootstrap() function
of S-Plus to the boot() function in the boot library of R (and also
S-Plus).<br><br>
Below is an example of one line from this S-Plus script. The
particular element I'm having trouble mapping to boot() is the <br>
group argument. This makes it pretty straightforward to work with
functions that operate on multiple groups. boot() has a strata
argument, which *seems* like it ought to be the rough equivalent of
group, but its operation is not entirely transparent. Can someone
point me to an example where boot() is used as I've illustrated below
with S-Plus' bootstrap() function? Unless I've missed something,
there isn't an illustration in VR3 or in the help for boot. (There
is a bivariate example, but the particular example doesn't translate well
to something like a discriminant analysis).<br><br>
Thanks for pointers.<br><br>
<br>
boot.lda.success<-bootstrap(apehum, hitratio(apehum[,1],
predict(lda(apehum[,2:11], apehum[,1]))$class)$error, group=apehum[,1],
trace=F, B=250)<br><br>
<br><br>
<br><br>
<br>
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=====================<br>
Dr. Marc R. Feldesman<br>
Professor and Chairman<br>
Anthropology Department<br>
Portland State University<br>
1721 SW Broadway<br>
Portland, Oregon 97201<br>
email: feldesmanm@pdx.edu<br>
phone: 503-725-3081<br>
fax: 503-725-3905<br>
http://web.pdx.edu/~h1mf<br>
PGP Key Available On Request<br>
======================<br><br>
"Anyway, no drug, not even alcohol, causes the fundamental ills of
society.<br>
If we're looking for the source of our troubles, we shouldn't test
people<br>
for drugs, we should test them for stupidity, ignorance, greed and love
of<br>
power." P.J. O'Rourke<br><br>
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