Hi, I'm a new user of R - Is this how you construct a hat matrix? H <- x %*% solve(t(x) %*% x) %*% t(x) H colnames(H) = rep('', 11) round(H,2) If so can you make them for more than 2 matrices? Why do you have to use the 2nd piece of code to round and stuff? Shouldn't it be correct from the start? Thanks for any feedback, Hyak -- View this message in context: http://r.789695.n4.nabble.com/Hat-Matrix-tp3759728p3759728.html Sent from the R help mailing list archive at Nabble.com.