You don't actually need Ben's example. The problem occurs also for the first example in ?nls if algorithm = "port" is used.
Peter Ehlers [EMAIL PROTECTED] wrote: > Duncan Murdoch wrote: > >>I've found the problem, but someone who knows more about nls() will have >>to fix it. >> >>The problem is that in the demo code below, n1 ends up being an nls >>object, but n1$call$control is NULL. profiler.nls() assumed that the >>nls object passed to it has a non-NULL element there, and doesn't check. >> >>I've fixed the code so now it doesn't crash, but it now dies with this >>error instead: >> >> > confint(n1) ## boom >>Waiting for profiling to be done... >>Error in prof$getProfile() : 'control$maxiter' absent >> >>I'll commmit my change to R-devel and R-patched shortly. >> >>Duncan Murdoch >> > > > thank you for the quick response! > > actually, I discovered I'm wrong -- bug affects Linux as well, > gives a segmentation fault > (I must have tried it without the algorithm="port" argument by > accident.) I've looked at the code but I regretfully concur > that someone else will have to work on this -- I can hack nls > so it reinserts a "control" element in n1$call, but $tol > and $minFactor are explicitly deleted from the control list, > and so we only get one step farther. I don't know what assumptions > nls_iter is really making and whether it's safe to make them > when the port algorithm is being used or not ... > > My best guess at this point, poking around, is that profiler.nls > in src/library/stats/R/nls-profile.R has to be changed in parallel > with nls to call port_nlsb instead of nls_iter when the port > algorithm is being used, but this is all getting a bit deep for > me ... > > Ben > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel -- Peter Ehlers Department of Mathematics and Statistics University of Calgary ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
