[R] nls model parameter compare?

Bert Gunter
Tue, 25 Aug 2015 22:59:53 -0000

This is a statistical question, and is off topic for this list, which
is about R programming. Post to a statistical list, like
stats.stackexchange.com, instead.

Warning: This is not a simple issue. You should seriously consider
getting local advice from someone with the necessary statistical
expertise.

Gratuitous Question born from personal frustration with such
queries(so feel free to ignore): Why are you using (statistical)
procedures that you do not understand? Of course the parameters for
different treatments are "different"! -- but how and with what
importance depends on the context in which you are working. Instead of
fooling with cryptic statistical mumbo jumbo that invite misuse -- and
which are probably valueless or idiotic anyway --  why don't you make
some graphs and consider what they say in terms of the substantive
issues at play? (Of course I know the answer -- it is because that is
what your academic culture/journals demand. But therein lies the
problem: what is demanded is junk).

Cheers,
Bert




Bert Gunter

"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
   -- Clifford Stoll


On Tue, Aug 25, 2015 at 3:34 PM, Jianling Fan <fanjianling at gmail.com>
wrote:
> Hello everyone,
>
> I am doing nonlinear regression using a same sigmoidal model for
> different treatments. for each treatment, I got a set of estimated
> parameters (a1, b1, c1 for treatment 1; a2, b2, c2 for treatment 2;
> a3, b3, c3 for treatment 3). And I want to compare these parameters
> for different treatments to see is there any differences? does
> estimated parameter for treatment i different from other treatments?
>
> How can I do this analysis please?
>
> Thanks in advance!
>
> Regards,
>
> Julian
>
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