Re: [R] How to get around heteroscedasticity with non-linear leas t squares in R?

From: Liaw, Andy <andy_liaw_at_merck.com>
Date: Wed 22 Feb 2006 - 05:56:39 EST


Your understanding isn't similar to mine. Mine says robust/resistant methods are for data with heavy tails, not heteroscedasticity. The common ways to approach heteroscedasticity are transformation and weighting. The first is easy and usually quite effective for dose-response data. The second is not much harder. Both can be done in R with nls().

Andy

From: Quin Wills
>
> I am using "nls" to fit dose-response curves but am not sure
> how to approach
> more robust regression in R to get around the problem of the my error
> showing increased variance with increasing dose.
>
>
>
> My understanding is that "rlm" or "lqs" would not be a good idea here.
> 'Fairly new to regression work, so apologies if I'm missing something
> obvious.
>
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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Wed Feb 22 06:01:00 2006

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