[R] how to plot implicit functions

[Duncan Murdoch]

YIHSU CHEN wrote:
> Dear R users --
>
> I think this question was asked before but there was no reply to it.
> I would appreciate any suggestion any of you might have.  I am
> interested in plotting several "implicit functions" (F(x,y,z)=0) on
> the same fig.     Is there anyone who has an example code of how to do
> this?
The misc3d package has a contour3d function that could draw a contour of 
the function F at level 0.  Assuming you have written a function to 
calculate F and know the region where you want to plot it, you could 
just say

contour3d(F, 0, seq(minx, maxx, 30), seq(miny, maxy, 30), seq(minz, 
maxz, 30)) 

Duncan Murdoch