Simple function to apply the Box Tidwell transformation to a variables in a formula. Variable is first shifted and scaled NewVar = (Var+shift)/scale then transformed and optionally centered. Can be used in formulas as poly() is.
fpTrans(var, powers = 1, scale = 1, shift = 0, center = TRUE)the variable to transform
one or more powers
value to scale the variable after shifting (default=1)
value to shift the variable by (default=0)
center the variable when tranforming.
the transformed vector