Le jeudi 03 mai 2012 à 07:37 -0700, agent dunham a écrit : > Dear community, > > I'm having this silly problem. > > I've a linear model. After fixing it, I wanted to know which data had > studentized residuals larger than 3, so i tried this: > > d1 <- cooks.distance(lmmodel) > r <- sqrt(abs(rstandard(lmmodel))) > rstu <- abs(rstudent(lmmodel)) > > a <- cbind( mydata, d1, r,rstu) > > alargerthan3 <- a[rstu >3, ] > > And suddenly a[rstu >3, ] has 17 rows, 7 of them are "new rows", where all > the entries are NA's, even its rownames. > > Because of this I'm not sure of the dimension of a[rstu >3, ] (Do I only > have 8 entries?) > > Has this happened to anybody before? If so, why this extra NA rows? what's > the problem? Is there any other way to know which data have studentized > residuals larger than 3? > > > if it's needed to upload my data, just tell me. A small reproducible example would have been better. Anyway, see page 88 of The R Inferno.
In your case, the simplest solutions are to do: alargerthan3 <- a[which(rstu > 3),] or alargerthan3 <- subset(a, rstu > 3) Cheers ______________________________________________ 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.
