Displaying 3 results from an estimated 3 matches for "ecoord2".
Did you mean:
coord2
2008 Oct 26
0
orthographic projection of ellipsoids
...ol=3)
> }
> rotM3d() # I
>
> ellipsoid <- # idea borrowed from a post in the R-mailing list
> (John Fox i think)
> function(x=0, y=0, z=0, radius=1, shape=diag(c(10, 2, 2)),theta=0,
> phi=0, psi=0, segments=11) {
> angles <- (0:segments)*2*pi/segments
> ecoord2 <- function(p) {
> c(cos(p[1])*sin(p[2]), sin(p[1])*sin(p[2]), cos(p[2]))
> }
> unit.sphere <- t(apply(expand.grid(angles, angles), 1, ecoord2))
> xyz <- t(c(x, y, z) + radius * rotM3d(theta, phi, psi)%*
> %t(unit.sphere %*% chol(shape)))
> chull(x=xyz[, 1], y=...
2012 Mar 09
2
rgl: cylinder3d() with elliptical cross-section
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,
2005 Oct 04
1
Rcmdr and scatter3d
Hi folks,
I'd like to use scatter3d (which is in R commander) to plot more than one
dataset in the same graph, each dataset with a different color. The kind
of stuff you would do with "holdon" in Matlab.
I read a recent message that was posted to this list with a similar
problem, but I couldn't understand the reply. Could someone give me one
example? How do you plot subgroups