[R] Extracting variance-covariance matrix from nlme object

[Rob Forsyth]

I want to extract the variance-covariance matrix of an nlme model of  
a dataset. The object is to pass this to mvrnorm to create pseudo- 
replicates of the original data. I note the nlme package has a  
getVarCov method available for lme objects but not nlme objects. Is  
the vcov function in the base stats package suitable? If so, why is  
the additional getVarCov provided?

thank you

Rob Forsyth