-----Original Message-----
From: Etsushi Kato [mailto:ekato at ees.hokudai.ac.jp]
Sent: Wednesday, September 12, 2001 8:43 AM
To: r-help at stat.math.ethz.ch
Cc: Prof Brian Ripley; Martyn Plummer
Subject: Re: [R] nonlinear fitting when both x and y having
measurement
e
Thank you very much Prof. Ripley and Martyn Plummer.
Also I got one suggestion of using ORDPACK at http://www.netlib.org/.
That is not a least-squares problem. Even in the simple
x one y) it's a hard problem, one that cannot be solved
information (for example on the ratio of the error
one of them). As far as I know there is no software
that case (although it's not hard to write).
My data is allometric relationship of biological data, and
perhaps it is
OK to assume both variables having equal accuracies. So I was just
considering using orthogonal distance to the nonlinear curve.
I think you need to write down a suitable likelihood and
numerically (with optim).
It's a bit difficult for me to construct likelihood function, because
right now there is no books you suggested around me...
For the moment, I'm considering using ORDPACK. I'll try to construct
R code later.
Best Regards,
--
Etsushi Kato
ekato at ees.hokudai.ac.jp
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