| carprice {DAAG} | R Documentation |
U.S. data extracted from Cars93, a data frame in the
MASS package.
carprice
This data frame contains the following columns:
MASS package
Venables, W.N. and Ripley, B.D., 3$^{rd}$ edn 1999. Modern Applied Statistics with S-Plus. Springer, New York.\ See also `R' Complements to Modern Applied Statistics with S-Plus, available from \ http://www.stats.ox.ac.uk/pub/MASS3/.
print("Multicollinearity - Example 6.8")
pairs(carprice[,-c(1,8,9)])
carprice1.lm <- lm(gpm100 ~ Type+Min.Price+Price+Max.Price+Range.Price,
data=carprice)
round(summary(carprice1.lm)$coef,3)
pause()
alias(carprice1.lm)
pause()
carprice2.lm <- lm(gpm100 ~ Type+Min.Price+Price+Max.Price+RoughRange, data=carprice)
round(summary(carprice2.lm)$coef, 2)
pause()
carprice.lm <- lm(gpm100 ~ Type + Price, data = carprice)
round(summary(carprice.lm)$coef,4)
pause()
summary(carprice1.lm)$sigma # residual standard error when fitting all 3 price variables
pause()
summary(carprice.lm)$sigma # residual standard error when only price is used
pause()
vif(lm(gpm100 ~ Price, data=carprice)) # Baseline Price
pause()
vif(carprice1.lm) # includes Min.Price, Price & Max.Price
pause()
vif(carprice2.lm) # includes Min.Price, Price, Max.Price & RoughRange
pause()
vif(carprice.lm) # Price alone