[R] Regression

[Chuck Cleland]

Alvaro wrote:
> I need to run a regression analysis with a large number of samples. Each
> sample (identified in the first file column) has its own x and y values. I
> will use the same model in all samples. How can I run the model for each
> sample? In SAS code I would use the "BY SAMPLE" statement.

  Here are a couple of ways:

by(warpbreaks, warpbreaks$tension, function(x) lm(breaks ~ wool, data = x))

library(nlme)

summary(lmList(breaks ~ wool | tension, warpbreaks))

?by

?lmList

>  
> 
> Alvaro
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-- 
Chuck Cleland, Ph.D.
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