Jari, thanks for the quick answer. > sqrt(eigen(cov.trob(mydataforellipse)$cov)$values)
what will this return? For my data, I get: > sqrt(eigen(cov.trob(r)$cov)$values) [1] 1.857733e-05 4.953181e-06 Is this Left hand value the major or the semi major length? I also try to plot a circuit keeping this as the radius/diameter I don't get a circle that intersects the major axis of the ellipse. Thanks !! Vishal. On Sep 2, 11:27 am, Jari Oksanen <jari.oksa...@oulu.fi> wrote: > Vishal <vishalps <at> gmail.com> writes: > > > > > I have a matrix(3000x2) of numbers and I have plotted a scatterplot > > (defined in the ``car'' library.) > > > scatterplot(r$V1,r$V2,ellipse=TRUE) > > > The ellipse plotted is an error ellipse. > > > I want the find the major(semi), minor(semi) minor axis length of this > > ellipse. > > If you have the ellipse from cov.trob(), then you could do like this > > sqrt(eigen(cov.trob(mydataforellipse)$cov)$values) > > Cheers, Jari Oksanen > > ______________________________________________ > r-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ 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.
