Plan <- read.table("https://husson.github.io/livre_exo/chap13_ex8.csv", header = TRUE, sep=";",row.names=1, encoding = "latin1")
for (i in 1:5) Plan[,i] <- as.factor(Plan[,i])

X <- model.matrix(~ F1+F2+F3+F4+F5, Plan, contrasts = "contr.sum")
t(X)%*%X
solve(t(X)%*%X)
library(FactoMineR)
AovSum(Y~F1+F2+F3+F4+F5, data=Plan)