Applying 'lm' in each group

Bhargab Chattopadhyay <bhargab_1 <at> yahoo.com> writes:

Hi,

?I want to?do regression?in each group. I made the group the following way.

Now I want to run regression

in each of the three groups..
Suppose , 
w

Now if I write lm(yg~xg) then it won't work. Please advice how to proceed.

Thanks in advance.

The one-liner is


mapply(function(x,y) lm(y~x,data=data.frame(x,y)),xg,yg,
       SIMPLIFY=FALSE)

Perhaps easier to understand:

results <- list()
for (i in seq(along=xg)) {
  results[[i]] <- lm(yg[[i]]~xg[[i]])
}

  Ben Bolker