[R] rgl: cylinder3d() with elliptical cross-section

[Michael Friendly]

For a paper dealing with generalized ellipsoids, I want to illustrate in 
3D an ellipsoid that is unbounded
in one dimension, having the shape of an infinite cylinder along, say, 
z, but whose cross-section in (x,y)
is an ellipse, say, given by the 2x2 matrix cov(x,y).

I've looked at rgl:::cylinder3d, but don't see any way to make it 
accomplish this.  Does anyone have
any ideas?

thx,
-Michael

-- 
Michael Friendly     Email: friendly AT yorku DOT ca
Professor, Psychology Dept.
York University      Voice: 416 736-5115 x66249 Fax: 416 736-5814
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