On Tue, 4 Dec 2007, Florencio González wrote:
Hi, I´m trying to plot a nonlinear regresion with the confidence bands for
the curve obtained, similar to what nlintool or nlpredci functions in Matlab
does, but I no figure how to. In nls the option is there but not implemented
yet.
Is there a plan to implement the in a relative near future?
No (and it is confidence intervals not confidence bands that are
unimplemented, and have been for years).
Doing what you ask (confidence bands) is very tricky indeed to do
accurately (and is not what nlpredci says it does), and even accurate
pointwise confidence intervals are problematic. See MASS4 sections
8.4/5 and its on-line complements for some details about why even
confidence intervals for parameters are frequently tricky in non-linear
models.
You could use resampling methods: see the reference in the previous
paragraph.
Thanks in advance, Florencio
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Brian D. Ripley, [EMAIL PROTECTED]
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