Bug variogram_model parameter ?

[mserouar]

Hi !
Thanks for this nice package.

I'm facing some issues using OrdinaryKriging function.
I set variogram_model as exponential, as lags follow empirically an exponential law.

However fitting seems ... weird ?
Am I missing something ? Thanks in advance !

[mserouar]

Using power instead seems also facing issues (maybe number of lags max ?)

giving