Ebrahim Jahanshiri wrote:
I am wondering if there is any function or option to back-transform the
result of the lognormal kriging in gstat yet.
You can use krigeTg, which does trans-Gaussian kriging for all Box-Cox
transforms; passing it a lambda parameter with value 0, log-normal
kriging is used. Pls look at the examples, the back-transformed values
have funny names like var1TG.pred.
The whole think has been implemented for ordinary kriging only; if
someone can point me out a source that describes how to do this for
universal / external drift kriging, I'd be happy to look into how to
implement it.
Although for simple kriging it is fairly straight forward, that is, it is
possible to do back-transform using the vector of predicted values and
kriging variances, but for ordinary kriging, it might be difficult because
we dont have lagrange multiplier (according to my web help search) to do the
back-transformation. I am wondering if there has been any advancement in
that matter?
thank you
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Edzer Pebesma
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