Help with accessing elements of a list

Hi,

As part of the analysis of a longitudinal study, I have a list, called wg,
on R 1.3.1 for windows created as follows -

wg <- by(xx, xx$mrn, function(xx) lm(xx$maternal.wt ~ xx$gestation,
data=xx))

It would be slightly more elegant (but equivalent) to write
 wg <- by(xx, xx$mrn, function(xx) lm(maternal.wt ~ gestation,  data=xx))

xx is a data.frame, and so wg contains the results of 293 linear
regressions, as lm objects.

Now what I want is to extract the 293 intercepts and regression coefficients
as a vector, and do things with them - like examine their distributions.

Well, if you had one of these you would use coef(one.of.these) to get the
coefficients, so given an entire list you could use
   sapply(wg,coef)
to return the 293x2 matrix of coefficients.

	-thomas

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