Use adjusted back-transformed mean for Box-Cox
transformations. If TRUE, point forecasts and fitted values are mean
forecast. Otherwise, these points can be considered the median of the
forecast densities.
fvar
Optional parameter required if biasadj=TRUE. Can either be the
forecast variance, or a list containing the interval level, and the
corresponding upper and lower intervals.
Value
a numeric vector of the same length as x.
Details
The Box-Cox transformation is given by $$f_\lambda(x) =\frac{x^\lambda -
1}{\lambda}$$ if \(\lambda\ne0\). For \(\lambda=0\),
$$f_0(x)=\log(x)$$.
References
Box, G. E. P. and Cox, D. R. (1964) An analysis of
transformations. JRSS B26 211--246.