Obtain vertices of the ellipse on an ellipse covariance plot (created by `car::ellipse`)
<p>By following <a href="https://stackoverflow.com/questions/15206970/drawing-ellipse-in-r">this post</a> one can draw an ellipse with a given shape matrix (A):</p>

<pre><code>library(car)
A &lt;- matrix(c(20.43, -8.59,-8.59, 24.03), nrow = 2)
ellipse(c(-0.05, 0.09), shape=A, radius=1.44, col="red", lty=2, asp = 1)
</code></pre>

<p>Now how to get the major/minor (pair of intersect points of the major/minor axis and the ellipse) vertices of this ellipse?</p>