HansDieter88 - 10 months ago 55

R Question

I´m trying to understand all the formulas around regression and am trying to calculate basically sum(xi-mean(x))^2 for a dataset.

Tried this:

`sum(pubs$pubs-mean(pubs$pubs))^2`

Answer

Usually you do the square first before summing, eg `sum((y - yhat)^2)`

; otherwise, you should get zero because `mean(x) = sum(x)/n`

and `sum(x-mean(x)) = sum(x) - n*mean(x)`

.

Source (Stackoverflow)