Ulrich Leopold wrote:
Antonio Gallardo wrote:
Hi all,
I am starting to work with GSTAT under R, and I would like to know whether
back-transformation (log transformation) of prediction results is possible
under GSTAT. Any suggestion is welcome.
Thanks in advance,
R can do the back-transform for you, if it's limited to simply calculating
the exponent. This gives you a median-type estimate on the original
scale. If you want an expectation-type estimate on the original
scale, you'd need the lagrange multiplier to do this and gstat does
not provide this as separate information; you'd have to modify it.
Is it difficult to modify the code?
I will need, to do POINT simulations of log-transformed data and
back-transform the points. Then aggregate the results to BLOCKS.
Ulrich
For back-transforming simulated values, you don't need any Lagrange
parameters; you only need it to back-transform the kriging estimate to
the log-normal kriging estimate.
--
Edzer
