[R] Tick marks in cloud (lattice)

[Pär Matsson]

Hi! Probably a simple question, but I can't get any tick marks in the 3d 
scatterplot I created using the cloud function.

The following works to display the three groups using different symbols:

data(iris)
cloud(Sepal.Length ~ Petal.Length * Petal.Width, data = iris, cex = 1.2, 
groups = Species, pch = c(16,1,1), col = c("black","black","red"), 
subpanel = panel.superpose, screen = list(z = 50, x = -80, y = 0), 
par.settings = par.set)

What should I add in order to get tick marks on the x, y, and z axes? I 
would like to use this for my own data, with tick marks preferably at 
defined positions [in original scale] for each axis.

Thanks for helping a beginner!
/Pär Matsson

-- 
Pär Matsson, M.Sc.
Dept. of Pharmacy
Uppsala University
Box 580
SE-751 23 Uppsala
Sweden

Phone: +46 (0)18 471 43 71
Cell: +46 (0)70 22 99 836
Fax: +46 (0)18 471 43 77
www.farmaci.uu.se
Par.Matsson at farmaci.uu.se