Displaying 1 result from an estimated 1 matches for "tp24156181p24160647".
2009 Jun 22
1
nls vs nlme: parameter constraints
Hello list,
I'm trying to fit a model like beta[trt]/(1+alpha*x) where the data
include some grouping factor. The problem is that the estimate for alpha
is undefined for some of the treatments - any value greater than 20 is
equally good and a step function would suffice. Ignoring the grouping
structure, I can fit this using nls with the port algorithm by
restricting the upper value of alpha