R/hat.plot.R

In trinker/Regression: Fuctions for linear models

hat.plot <-
function(fit) {
              p <- length(coefficients(fit))
              n <- length(fitted(fit))
              plot(hatvalues(fit), main="Index Plot of Hat Values")
              abline(h=c(2,3)*p/n, col="red", lty=2)
              identify(1:n, hatvalues(fit), names(hatvalues(fit)))
            }