A helper function for sem.coefs that provides a scaled data frame (by mean and standard deviation, or range).
get.scaled.data(modelList, data, standardize)a list of regressions representing the structural equation model.
a data.frame used to construct the structured equations.
specifies the type of standardization to perform: "none", "scale", "range".
Returns a data.frame with the scaled (transformed) variables.
Automatically calculates and scales variables that are transformed in the model formulae.