How to use gstat 'variogram' function for nonlinear formulae?

Dear all,


For a linear model I use the 'variogram' function in gstat as follows:


coordinates(data) <- c('x','y')
myvario <- variogram(dep~var1+var2+var3, data)

Now, I have the following Nonlinear formula that I want to use in variogram.

dep~ var1*var2^3


My 2 questions are:

i) Can the variogram function in gstat handle nonlinear models as this formula?

ii) What is the syntax to use this nonlinear formulae within the variogram function? is it simply :

myvario <- variogram(dep~ var1*var2^3, data)

Any advice is appeciated.


cheers

Chris Akram