Is anyone able to offer a reason that, when using weights in an lm fit, the Cook's distances shown in plot.lm(x, which=4) differ from those calculated by cooks.distance(x) ?
I can see that they _are_ different and the code tells me _how_ they differ (essentially, one is using the weights and the other isn't). My question is _why_ different calculations are chosen. Example: set.seed(1023) x<-1:10 s <- (x)/10 y <- rnorm(10, x, s) l <- lm(y~x, weights=1/s^2) par(mfrow=c(2,1)) plot(l, which=4) plot(cooks.distance(l), type="h", main="cooks.distance(l)") S Ellison ******************************************************************* This email and any attachments are confidential. Any use...{{dropped:8}} ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.