3D or 4D plot

On 2/20/2009 1:55 PM, Duncan Murdoch wrote:

On 2/20/2009 1:46 PM, kapo coulibaly wrote:

Ideally I would want it to look like a rubik cube with each little cube
color coded based on the fourth column (data column). Your suggestion might
work if I could color code based on data in the fourth column.
Thanks

There's no primitive "cube" symbol in rgl, but you can get an array of
colour-coded spheres:

x <- rep(1:3, each=9)
y <- rep(rep(1:3, each=3), 3)
z <- rep(1:3, 9)
colours <- terrain.colors(27)
plot3d(x,y,z,col=colours, type="s", size=10)

If you really want cubes, you can put them together (start with cube3d()
to get one, and build on that), but it's a lot of work.

But it's Friday, so fun things like that are worth doing. ?Here's some
code to draw a bunch of cubes with a variety of colours. ?Elaborate on
it if you like.

Duncan Murdoch

cubes3d <- function(x,y,z,col="red",size=0.9,plot=TRUE) {

? ? ?xyz <- xyz.coords(x, y, z, recycle = TRUE)
? ? ?x <- xyz$x
? ? ?y <- xyz$y
? ? ?z <- xyz$z

? ? ?col <- rep(col, len=length(x))
? ? ?size <- rep(size/2, len=length(x))

? ? ?result <- list(vb=matrix(0, 4, 0), ib=matrix(1L, 4, 0),
primitivetype="quad",
? ? ? ? ? ? ? ? ? ? material=list(color=NULL, normals=NULL))
? ? ?class(result) <- "qmesh3d"

? ? ?for (i in seq_along(x)) {
? ? ? ? cube <- translate3d(scale3d(cube3d(), size[i], size[i],
size[i]), x[i], y[i], z[i])
? ? ? ? offset <- ncol(result$vb)
? ? ? ? result$vb <- cbind(result$vb, cube$vb)
? ? ? ? result$ib <- cbind(result$ib, cube$ib + offset)
? ? ? ? result$material$color <- c(result$material$color, rep(col[i],
4*ncol(cube$ib)))
? ? ?}
? ? ?if (plot)
? ? ? ? shade3d(result)
? ? ?invisible(result)

}

x <- rep(1:5, each=25)
y <- rep(rep(1:5, each=5), 5)
z <- rep(1:5, 25)
cubes3d(x,y,z,col=terrain.colors(125))