[R] R.squared in summary.lm with weights

[hd625b]

Do you mean w <-  z$residuals ?
Type names(z) to see the list of item in your model.

I ran your code on a lm and it work fine.
You don't need the brackets around mss <-

Michael Long



On 04/07/2016 02:21 PM, Murray Efford wrote:
> Following some old advice on this list, I have been reading the code for summary.lm to understand the computation of R-squared from a weighted regression. Usually weights in lm are applied to squared residuals, but I see that the weighted mean of the observations is calculated as if the weights are on the original scale:
>
> [...]
>      f <- z$fitted.values
>      w <- z$weights
> [...]
>              m <- sum(w * f/sum(w))
>              [mss <-]  sum(w * (f - m)^2)
> [...]
>
> This seems inconsistent to me. What am I missing?
>
> Murray Efford
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