R help - Oct 2007 - calculate residue by groups

Hi Folks,

I want to get the regression residue which each Race. But using:
sample$resid <- by(sample,sample$Race),function(x)resid(lm( stroke ~ Sex +
Age + Smoker + BMI, data = x)))
Does not work. How do I calculate residue by grops?

thanks.

jiong
 The email message (and any attachments) is for the sole...{{dropped:11}}

Hi,

Works for me:

samp$Resid <- as.numeric(do.call("c",by(samp, samp$Race,
function(x)resid(lm(stroke~Sex+Age, data=x)))))


On 24/10/2007, Jiong Zhang, PhD <jizhang@chori.org>
wrote:
>
> Hi Folks,
>
> I want to get the regression residue which each Race. But using:
> sample$resid <- by(sample,sample$Race),function(x)resid(lm( stroke ~ Sex
+
> Age + Smoker + BMI, data = x)))
> Does not work. How do I calculate residue by grops?
>
> thanks.
>
> jiong
> The email message (and any attachments) is for the sol...{{dropped:20}}