[R] Compare linear regressios for significant differences of the slopes

[Rainer M Krug]

Hi

I haven't received any ideas yet - I just wanted to confirm if this is a 
simple question? Should I follow the idea of checking if slope +- stddev 
slope overlap?

Thanks,

Rainer

Rainer M Krug wrote:
> Hi
> 
> I have (8 measures * 96 groups) = 768 datasets for which I did linear
> regressions using lm().
> 
> Now I want to compare the slopes for each of the 8 measures in each of 
> the 96 groups. As I understand , I can not use
>> anova(lm1, ..., lm8)
> as the lm1 ... lm8 are based on different datasets.
> 
> I also read in previous discussions in this list, that I can see if the 
> slope +- stddev(slope) overlap, but this seems a long process for the 
> huge number of comparisons.
> 
> Therefore my question: is there a way to compare the slopes of lm() 
> which are based on different datasets and what is the easiest way to do
> it for this large number of datasets?
> 
> Thanks in advance for your help,
> 
> Rainer
> 


-- 
Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation
Biology (UCT)

Department of Conservation Ecology and Entomology
University of Stellenbosch
Matieland 7602
South Africa

Tel:		+27 - (0)72 808 2975 (w)
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email:	RKrug at sun.ac.za
       	Rainer at krugs.de