[R] regression by groups

[Chuck Cleland]

Jiong Zhang, PhD wrote:
> Hi All,
> 
> I want to run regression (lm) on my dependant variable by gender and race. How do I integrate the "by" function in lm?
> 
> thanks.

  Here is an example using the iris data:

by(iris, iris$Species, function(x){
summary(lm(Sepal.Length ~ Sepal.Width +
                          Petal.Length +
                          Petal.Width, data=x))})

> jiong
>  The email message (and any attachments) is for the sole...{{dropped:11}}
> 
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-- 
Chuck Cleland, Ph.D.
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