# “Nonlinear” random spatial field: an example

I want to generate a "nonlinear" random spatial field in the sense that the autocorrelation function in function of the lag/distance $$h$$, $$\rho(h)$$, should be not equal to the $$R(h)$$ coefficient that is $$R(h) = \sqrt{1-exp(-2I(h))}$$, where $$I(h)$$ is the mutual information in function of the lag/distance h. Any suggestions?