search for: ellipse3d

Last week I asked about data ellipses with rgl:::ellipse3d() with lines showing the principal axes. (The goal is a visual demonstration of PCA as a rotation of variable space to component space.) I was trying, unsuccessfully, to use princomp() to generate the PCA axes and plot them using segments3d: > > PC <- princomp(trees) > > sdev &lt...

...f the ellipse as vectors. library(rgl) data(trees) cov <- cov(trees) mu <- mean(trees) plot3d(trees, type="s", size=0.5, col="blue", cex=2) In this step, an extra box is added. I've tried using box=FALSE, but it has no effect. # how to avoid the extra box? plot3d( ellipse3d(cov, centre=mu, level=0.68), col="pink", alpha=0.2, add = TRUE) Here's what I've tried to plot the principal axes in variable space, using the result of prcomp(). But I've got something wrong, because, although they are at right angles, they don't align with the ellip...

...scene using rgl.postscript() R crasches .########### plot3d(datii[,1:3],box=F,col=datii[,5],type="s",radius=datii[,4]/10,add=T,bbox=F) #### MINOR PROBLEM: these are the 95% ellipses for any group; when saving using rgl.postscript() IN ANY FORMAT the transaparencies are lost #### plot3d(ellipse3d(cov(subset(datii[,1:3],datii[,5]==1)),centre=c(mean(subset(datii[,1],datii[,5]==1)),mean(subset(datii[,2],datii[,5]==1)),mean(subset(datii[,3],datii[,5]==1)))),col=1,alpha=0.3,add=T) plot3d(ellipse3d(cov(subset(datii[,1:3],datii[,5]==2)),centre=c(mean(subset(datii[,1],datii[,5]==2)),mean(subset(dat...

...XY plane as in Figure 5.2 in this text<http://books.google.com/books?id=PMeJGeXA09EC&pg=PA172&dq=confidence+ellipsoid&hl=en&sa=X&ei=oWQxT4OgBYLSiALW85WtAw&ved=0CEIQ6AEwAg#v=onepage&q=confidence%20ellipsoid&f=false> . Is this possible using some combination of ellipse3d() and ellipse()? Any insights would be greatly appreciated. Thanks. [[alternative HTML version deleted]]

Dear List, I don't get scatter3d to color the sheres according to the '|' argument. library(car) scatter3d(prestige ~ income + education|type, data=Prestige) The spheres on my screen are all colored the same and they are not conditional on Prestige$type. On the other hand: Fit3d and Ellipse3d are colored according to the group argument. rgl_0.92.879 car_2.0-12 R version 2.15.0 i686-pc-linux-gnu (32-bit) I checked this under windows and: here they are colored according to 'Prestige$type'. Hmm? What goes wrong here, any ideas? thanks, Ren?

Dear list, I'm trying to visualise some ellipsoidal shapes in 3D. Their position, axes, and angular orientation can be arbitrary. I saw an ellipse3d function in rgl; however it is heavily oriented towards the statistical concept of ellipse of confidence, whilst I am just concerned with the geometrical object. Below is my current implementation. It is quite slow when creating many shapes, so I'm asking for suggestions (I'm new to rgl),...