[R] simplest possible xyz plot

[Thomas Lumley]

On Wed, 29 Dec 2004, t takahashi wrote:

> New to R, and didn't find the following in the docs.
>
> Main use for R. to get feet wet, is to pipe in x,y,z data, one point
> per line, and
> plot it in 3d, like this:
>
> {
> echo 1,2,3
> echo 2,4,6
> ...
> } | R ...
>
> But functions like contour seem to require index vectors that are
> sorted.  I am curious why, and how to convert.
>

In addition to Uwe's points, if the elevation data are in a matrix then 
these functions do not require any index vectors.

 	-thomas