Hello, I use nls.profile to compute confidence intervals of parameter estimates of a non-linear model. When computing the profiles, the model function produces an error for certain parameter combinations. Therefore nls fails and so does nls.profile. Is there a way to tell nls.profile to ignore errors and to proceed with the next parameter value? Cheers, Daniel. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 490 bytes Desc: This is a digitally signed message part URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20110331/8838c0d5/attachment.bin>
On Thu, Mar 31, 2011 at 4:02 AM, Daniel Kaschek <daniel.kaschek at physik.uni-freiburg.de> wrote:> Hello,> I use nls.profile to compute confidence intervals of parameter estimates > of a non-linear model. When computing the profiles, the model function > produces an error for certain parameter combinations. Therefore nls > fails and so does nls.profile.> Is there a way to tell nls.profile to ignore errors and to proceed with > the next parameter value?Not easily. What I tend to do is to adjust (increase) the alphamax parameter (which is a misnomer, it should have been alphamin but I got confused) until the profile can succeed.
Hello Daniel, I have the same problem than you : i use nls.profile to compute confidence intervals of estimated parameters but it fails and stop... I tried to increase alphamax value as Douglas suggested that it should work but it's not... Did you find a method to tell nls.profile to ignore errors and proceed to the next parameter value ? Thank you very much! -- Thomas de Marchin PhD Student Laboratory of Bioenergetics University of Li?ge, Institute of Botany (B.22-P.70) Bld du Rectorat, 27 Sart Tilman, 4000 Li?ge, Belgium Tel: +32 (0)4 366 38 08 http://www.biophoto.ulg.ac.be