Hi,
Thank you for the pointer, I will make the default in my code optim.
As I specified in my last post it may be my installation. In this
case the problem is that the third parameter (xmid) goes negative and
the log(xmid) fails in the parameterization I am using. For some
reason nlminb is not exi
Hi,
I was just able to try this on a windows xp machine
using R-2.5.1. gnls exits gracefully with an error
so maybe this is a problem with my R installation. If
so sorry to bother everyone. Does anyone have an idea
which installation parameters to tweek that might cure
this?
Thanks
Nicholas
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On Thu, 18 Oct 2007, Nicholas Lewin-Koh wrote:
> Hi,
> Following up on my own post, if in gnlsControl I specify
> opt='optim' gnls exits quite nicely, with an error, which
> is what I would expect. Is this a bug in nlminb?
Possibly, but complex algorithms can loop for non-bug reasons. I don't
f
Hi,
Following up on my own post, if in gnlsControl I specify
opt='optim' gnls exits quite nicely, with an error, which
is what I would expect. Is this a bug in nlminb?
Nicholas
tt<-gnls(response~SSllogis(conc,A,B,xmid,scal),tdat,start=start,weights=varPower(),verbose=TRUE,control=gnlsControl(opt
Hi,
I am not sure this is a bug but I can repeat it, The functions and data
are below.
I know this is nasty data, and it is very questionable whether a 4pl
model
is appropriate, but it is data fed to an automated tool and I would
have hoped for an error. Does this repeat for anyone else?
My details
