[R] comparing length-weight regressions]

From: Rubén Roa-Ureta <rroa_at_udec.cl>
Date: Thu, 20 Mar 2008 09:40:28 -0400


saduria_at_hotmail.com wrote:
> I'd like to compare length-weight regressions among years. Any information would be appreciated.
>
> a. gray
> fisheries consultant

Your message is rather cryptic for a general statistical audience, whereas I'm sure in a fisheries group everybody would understand what you want.
Use a glm with family=Gaussian(link=log) for all data sets together (in original units) with year as a factor, then run the model again ignoring the year factor, and compare the different fits using anova(name of your glm objects) for a likelihood ratio test, or inspect the AICs for a non-frequentist model selection method.
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. Received on Thu 20 Mar 2008 - 13:57:15 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Thu 20 Mar 2008 - 14:00:23 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive