zs {MASSExtra}

Standardisation functions for models

Description

These functions are for use in fitting linear models (or allies) with scaled predictors, in such a way that when the fitted model objects are used for prediction (or visualisation) the same scaling parameters will be used with the new data.

Usage

zs(x)

zu(x)

zr(x)

zq(x)

Arguments

x

A numeric vector

Value

a standardised vector containing the parameters needed for use in prediction with new data

Examples

fm <- lm(Gas ~ Insul/zs(Temp), whiteside)
gm <- lm(Gas ~ Insul/zu(Temp), whiteside)
hm <- lm(Gas ~ Insul/Temp,     whiteside)
c(fm = unname(predict(fm, data.frame(Insul = "Before", Temp = 0.0))),
  gm = unname(predict(gm, data.frame(Insul = "Before", Temp = 0.0))),
  hm = unname(predict(hm, data.frame(Insul = "Before", Temp = 0.0))))
rm(fm, gm, hm)