This function converts a transformation name to the corresponding function. Convertion is from original scale to real scale by default. Available transformations:
exp4: $(4x)$, inverse is $(x)/4$
exp2: $(2x)$, inverse is $(x)/2$
tanh: Hyperbolic tangent transformation used for AR1 parameter, uses ar1_th2a and ar1_a2th
identity: Identity function, no transformation
exp: $(x)$, inverse is $(x)$
sqrt: $(x)$, inverse is $x^2$
square: $x^2$, inverse is $(x)$
log: $(x)$, inverse is $(x)$
name2fun(trans, inv = FALSE)A function that applies the specified transformation