3D surface plot of nongridded x,y,z

[Bill Simpson]

I want to produce a 3D plot of some x,y,z data where x and y are random
(nongridded). An example is the heights of trees (z) in a forest (at
random x,y locations). I want a plot that uses Delaunay triangulation and
makes a triangular mesh.

In Matlab it would go like this
> % Generate some data:
> x = randn(1,200);
> y = randn(1,200);
> r = sqrt(x.^2 + y.^2);
> z = exp(-r.^2);
>
> % Do the plot:
> tri = delaunay(x,y);
> trisurf(tri,x,y,z)
>
Can I do this in Octave?

Thanks very much for any help.

Best wishes,
Bill Simpson