An eh transformation is a data transformation obtained by applying the function EH described in what follows to a (one dimensional) real number input. EH(x)=exp(x*d/r)+b*(d/r)*x-1, if x>=0, and EH(x)=-exp(-x*d/r)+b*(d/r)*x+1, otherwise. Here exp denotes an exponential transformation and b, d, r are positive real constants with the objective of normalization.