[R] geoR question from new R user

[Sharon Lambert]

Hi,

I'm a new R user. My goal is to do a variogram using geoR.
I started by trying to do the example in the geoR Illustrative Session 
using my own data.

I am able to read in my Ascii data using: D <- matrix(scan("file.dat", 
n=530*3), 530,3, byrow=TRUE).

Then I use: as.geodata(D, coords.col=1:2, data.col=3) to make the 
object D geodata.

I check the descriptive statistics, and my data file appears to be in 
order.

But when I try the following command:  cloud1<- variog(D, 
option="cloud", max.dist=1), I get this error:
    Error in array(x, c(length(x), 1), if (!is.null(names(x))) list
(names(x),  : 
        attempt to set an attribute on NULL

I get that same error message when I try different arguments with the 
variog command. 

Can someone help?

Thanks,

Sharon