Hello,

I have several questions for sketching a 3D graph using R. I will appreciate if I you could help. Here are my questions:

1. How to sketch a function such as z=f(x,y)= 1 (or x+y, etc.) where 0<x<y<1, using R?

2. I know box3d can be used to plot a box with two points, such as (0,0,0) and (2,2,2). How can we put another box, with (0,0,0) and (1,1,2) inside of that box?

3. In 2D, we can plot (x,f(x)) and then use lines(x,g(x)) to plot two functions in the same plane. How can we do the same for 3D?

Thanks,

Darius