On Apr 23, 2011, at 8:38 PM, Julian Gilbey wrote:
Hello! I have a set of data of the form (x, y1, y2) where x is the independent variable and (y1, y2) is the response pair. The model is some messy non-linear function: (y1, y2) = f(x; param1, param2, ..., paramk) + (y1error, y2error) where the parameters param1, ..., paramk are to be estimated, and I'll assume the errors to be normal for sake of simplicity. If there were only one response per input, I would use the nls() function, but what can I do in this case?
I wonder it would be sensible or at least informative to consider solving for the "inverse case". i.e. solve for:
x = f(y1, y2) -- David Winsemius, MD West Hartford, CT ______________________________________________ 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.
