| npk(MASS) | R Documentation |
A classical N, P, K (nitrogen, phosphate, potassium) factorial experiment on the growth of peas conducted on 6 blocks. Each half of a fractional factorial design confounding the NPK interaction was used on 3 of the plots.
block |
which block (label 1 to 6). |
N |
indicator (0/1) for the application of nitrogen. |
P |
indicator (0/1) for the application of phosphate. |
K |
indicator (0/1) for the application of potassium. |
yield |
Yield of peas, in pounds/plot (the plots were (1/70) acre). |
The npk data frame has 24 rows and 5 columns:
Imperial College, London, M.Sc. exercise sheet.
data(npk)
npk.aov <- aov(yield ~ block + N*P*K, npk)
npk.aov
summary(npk.aov)
alias(npk.aov)
coef(npk.aov)
options(contrasts=c("contr.treatment", "contr.poly"))
npk.aov1 <- aov(yield ~ block + N + K, npk)
summary.lm(npk.aov1)
se.contrast(npk.aov1, list(N=="0", N=="1"), data=npk)
model.tables(npk.aov1, type="means", se=TRUE)