Hi Antoon, now that you mention trying out different methods, maybe you should consider fitting a sigmoidal curve to the entire dataset and not only the exponential part (which constitutes a very small dataset) as seems to have been the endeavour that initiated the posting to R-help.
One options would then be to use the package qpcR and simply fitting a sigmoidal model using for instance drm() in the package drc or nls() combined with SSfpl(). Just a suggestion. Christian ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
