> On Mar 3, 2018, at 3:04 PM, Christien Kerbert <christienkerb...@gmail.com> > wrote: > > Dear list members, > > I want to perform an MM-regression. This seems an easy task using the > function lmrob(), however, this function provides me with NA coefficients. > My data generating process is as follows: > > rho <- 0.15 # low interdependency > Sigma <- matrix(rho, d, d); diag(Sigma) <- 1 > x.clean <- mvrnorm(n, rep(0,d), Sigma)
Which package are you using for mvrnorm? > beta <- c(1.0, 2.0, 3.0, 4.0) > error <- rnorm(n = n, mean = 0, sd = 1) > y <- as.data.frame(beta[1]*rep(1, n) + beta[2]*x.clean[,1] + > beta[3]*x.clean[,2] + beta[4]*x.clean[,3] + error) > xy.clean <- cbind(x.clean, y) > colnames(xy.clean) <- c("x1", "x2", "x3", "y") > > Then, I pass the following formula to lmrob: f <- y ~ x1 + x2 + x3 > > Finally, I run lmrob: lmrob(f, data = data, cov = ".vcov.w") > and this results in NA coefficients. It would also be more courteous to specify the package where you are getting lmrob. > > It would be great if anyone can help me out. Thanks in advance. > > Regards, > Christien > > [[alternative HTML version deleted]] This is a plain text mailing list although it doesn't seem to have created problems this time. > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. David Winsemius Alameda, CA, USA 'Any technology distinguishable from magic is insufficiently advanced.' -Gehm's Corollary to Clarke's Third Law ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.