[Rd] nlm and optional arguments
Ben Bolker
bolker@zoo.ufl.edu
Mon, 6 Mar 2000 16:55:12 -0500 (EST)
It would be really nice if nlm took a set of "..." optional arguments
that were passed through to the objective function. This level of hacking
is probably slightly beyond me: is there a reason it would be technically
difficult/inefficient? (I have a vague memory that it used to work this
way either in S-PLUS or in some previous version of R, but I could easily
be wrong.)
Here's a hack in R code that works for me (basically copying the R code
of nlm() but defining a temporary function that passes the optional
arguments to the objective function), but I presume this would be cleaner
and faster if implemented at a lower level ...
nlm2 <- function(f, p, hessian=FALSE, typsize=rep(1,length(p)),
fscale=1, print.level=0, ndigit=12, gradtol=1e-6,
stepmax=max(1000 * sqrt(sum((p/typsize)^2)), 1000),
steptol=1e-6, iterlim=100, check.analyticals=TRUE, ...) {
tmpf <- function(x) {
f(x,...)
}
nlm(tmpf,p,hessian=hessian,typsize=typsize,fscale=fscale,print.level=print.level,
ndigit=ndigit,gradtol=gradtol,stepmax=stepmax,steptol=steptol,iterlim=iterlim,
check.analyticals=check.analyticals)
}
As a matter of general principle, would the R-core folks prefer that
"wishlist" items like this get sent to R-bugs (so they can be kept better
track of) or not (so they don't clutter up the bugs database) ?
--
Ben Bolker bolker@zoo.ufl.edu
Zoology Department, University of Florida http://www.zoo.ufl.edu/bolker
318 Carr Hall/Box 118525 tel: (352) 392-5697
Gainesville, FL 32611-8525 fax: (352) 392-3704
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