Hi,
I have noticed that there is a change in the use of ellipses or . in R
versions 2.6.1 and later. In versions 2.5.1 and earlier, the . were
always
at the end of the argument list, but in 2.6.1 they are placed after
the main
arguments and before method control arguments. This results in the
user
having to specify the exact (complete) names of the control
arguments, i.e.
partial matching is not allowed.
An example with integrate() :
integrate(function(x) exp(-x^2), lower=-Inf, upper=L, subdiv=1000)
Error in f(x, ...) : unused argument(s) (subdiv = 1000)
integrate(function(x) exp(-x^2), lower=-Inf, upper=L,
subdivisions=1000)
1.633051 with absolute error < 1.6e-06
Here is an example with optim():
res <- optim(50, fw, meth="BFGS", control=list(maxit=20000, temp=20,
parscale=20))
Error in fn(par, ...) : unused argument(s) (meth = "BFGS")
FYI, I am using R version 2.6.1 on Windows XP.
May I ask what the rationale behind this change is and also about
the pros
and cons of the two different ways of specifying (.)?
Thank you very much.
Best,
Ravi.
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Ravi Varadhan, Ph.D.
Assistant Professor, The Center on Aging and Health
Division of Geriatric Medicine and Gerontology
Johns Hopkins University
Ph: (410) 502-2619
Fax: (410) 614-9625
Email: rvaradhan at jhmi.edu
Webpage: http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html
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