[R] Starting estimates for nls Exponential Fit

Christian Ritz ritz at life.ku.dk
Tue Dec 8 14:33:44 CET 2009

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

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.


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