R help - Mar 2009 - help with 3-D plot of kernel density estimates

Hi,
I guess I have a naive question. I use kde2d function in a standard way to
estimate kernel densities of x and y (x and y are vectors) and plot them
using image().

f1=kde2d(x,y)
image(f1)

But what if I want to see kernel estimates of three variables, x, y and z (a
vector) plotted together ? Something in which x<->y is plotted and colored
according to the corresponding value of z ?


thanks
Josh

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On 17/03/2009 6:44 AM, Josh wrote:
> Hi,
> I guess I have a naive question. I use kde2d function in a standard way to
> estimate kernel densities of x and y (x and y are vectors) and plot them
> using image().
> 
> f1=kde2d(x,y)
> image(f1)
> 
> But what if I want to see kernel estimates of three variables, x, y and z
(a
> vector) plotted together ? Something in which x<->y is plotted and
colored
> according to the corresponding value of z ?

See the kde3d example in the misc3d package for contour plots of a 3d 
density function (not as you described, but very nicely done).

Or if you just want 3d plots of a 2d function, you can use persp (from 
graphics) or persp3d (from rgl).

Duncan Murdoch