[R] Ellipse: Major Axis Minor Axis

[Vishal]

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... at 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... at 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.