[R] Ellipse: Major Axis Minor Axis

[Vishal]

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... 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
>
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