Adding plane in a 3D scatterplot

library(mnormt)
library(scatterplot3d)
dat = cbind(rmnorm(3, rep(0,2), diag(2)), 1:3)
s3d <- scatterplot3d(dat, lab.z=2, scale.y=0.7, angle=20)
s3d$plane3d(2,0,0, "solid", col="grey")

R.Version()

From: Uwe Ligges <ligges at statistik.tu-dortmund.de>
Subject: Re: [R] Adding plane in a 3D scatterplot
To: megh700004 at yahoo.com
Cc: r-help at stat.math.ethz.ch
Date: Thursday, October 2, 2008, 11:38 PM
Megh Dal wrote:

I have drawn a 3D scatter plot :

library(mnormt)
library(scatterplot3d)
dat = cbind(rmnorm(3, rep(0,2), diag(2)), 1:3)
scatterplot3d(dat)

Now I want to do 2 things :

1 : In the Z-axis (i.e. height), I want to see only

numbers 1,2,3, etc NOT, 1,1.5,2,2.5.............

2. I want to add two Horizontal planes at hight z=2

and z=3. Those two planes should look like
"bottom" of that 3D plot [i.e. like Grid-lines].I
already gone through "$plane3d" but could not get
through. In the help page, a description is given with a
regression line, however I could not understand how I can
implement that in my problem. 

Example:

  s3d <- scatterplot3d(dat, lab.z=2, scale.y=0.7,
angle=20)
  s3d$plane3d(2,0,0, "solid",
col="grey")

Uwe Ligges

Any help will be highly appreciate. 

Regards,