The yield of a petroleum refining process with four covariates.
The crude oil appears to come from only 10 distinct samples.
These data were originally used by Prater (1956) to
build an estimation equation for the yield of the refining
process of crude oil to gasoline.
The variables are as follows
N. H. Prater (1956)
Estimate gasoline yields from crudes.
Petroleum Refiner
35, 236-238.
This dataset is also given in
D. J. Hand, F. Daly, K. McConway, D. Lunn and E. Ostrowski (eds) (1994)
A Handbook of Small Data Sets.
Chapman & Hall.
pet3.lme <- lme(Y ~ SG + VP + V10 + EP, random = ~ 1 | No, data = Petrol) pet3.lme <- update(pet3.lme, method = "ML") pet4.lme <- update(pet3.lme, fixed = Y ~ V10 + EP) anova(pet4.lme, pet3.lme)