I forgot to mention that the ellipse has a rotation. It's horizontal axis is not parallel to the x-axis.
Just repeating, when I try to draw a circuit keeping the center same as the ellipse, and radius equal to the first value returned by > sqrt(eigen(cov.trob(mydataforellipse)$cov)$values) taking it to be the semi-major axis, I don't see the circle encapsulating the ellipse. Am I fundamentally missing something? Thank you!! 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.
