[R] R² for non-linear model + comparing linear + non-linear models

[Anna Gretschel]

Am 16.03.2011 19:29, schrieb Heiman, Thomas J.:
> Hi Anna,
>
> AIC and BIC are good criteria for determining degree of model fit..
>
> Sincerely,
>
> tom
>
> Thomas Heiman, PhD
> Info Systems Eng, Sr
> The MITRE Corporation | Center for Enterprise Modernization
> Office: 703-983-2951 | theiman at mitre.org
>
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Anna Gretschel
> Sent: Wednesday, March 16, 2011 2:09 PM
> To: Bert Gunter
> Cc: r-help at r-project.org
> Subject: Re: [R] R² for non-linear model + comparing linear + non-linear models
>
> Dear Bert,
>
> so what can I do to obtain a goodness of fit for a non-linear model if
> r² does not work?
>
> And here comes my next question: is it apropriate to comopare a linear
> and a non-linear model with anova()?
>
> Thank you so much for answering,
> Anna
>
>
>
> Am 16.03.2011 18:54, schrieb Bert Gunter:
>> Is there any way that this could be made into a fortune -- perhaps by
>> omitting the poster's identity?
>>
>> "yes there are threads concidering this topic but they are all about the
>> theory not about how to get the value of r^2 for a non-linear model in R."
>>
>> :=)
>>
>> Cheers,
>> Bert
>>
>> Anna: I say this because you have just been told that the "theory"
>> tells you that you CANNOT calculate R^2 for a nonlinear model.
>>
>>
>> On Wed, Mar 16, 2011 at 10:25 AM, Anna Gretschel<ana-lee at web.de>   wrote:
>>> Am 16.03.2011 18:15, schrieb David Winsemius:
>>>> On Mar 16, 2011, at 12:53 PM, Anna Gretschel wrote:
>>>>
>>>>> Dear List,
>>>>>
>>>>> how can I obtain the value of r suqared for a non-linear model? For
>>>>> linear models it can be found in the summary() of the model but for
>>>>> non-linear models I just don't know. Please help!
>>>> You should do more searching. I can remember at least two threads in the
>>>> last few years that discussed this issue.
>>>>
>>> yes there are threads concidering this topic but they are all about the
>>> theory not about how to get the value of r^2 for a non-linear model in R.
>>>
>>> ______________________________________________
>>> R-help at 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.
>>>
>>
> ______________________________________________
> R-help at 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.
>
Thank you so much! Anna