# create the bhhTCK data set used in ExptDesign
Temp = factor(rep(c(160,180),times = 4),levels=c(160,180)) # temperature
Conc = factor(rep( c(20,40), each = 2, times = 2),levels=c(20,40))  #concentration
Cat =  factor(rep( c("A","B"), each=4),levels=c("A","B"))  # catalyst
contrasts(Temp) <- contrasts(Conc) <- contrasts(Cat) <- contr.helmert(2)
yield = c(60,72,54,68,52,83,45,80)
bhh <- data.frame(Temp,Conc,Cat,yield)

T2 <- bhh$Temp == "180" ; T1 <- bhh$Temp == "160" 
C2 <- bhh$Conc == "40" ; C1 <- bhh$Conc == "20" 
K2 <- bhh$Cat == "B" ; K1 <- bhh$Cat == "A" 

B <- data.frame(int=1, t=T2-T1, c=C2-C1, k=K2-K1)
B$tc <- B$t * B$c ; B$tk <- B$t * B$k ; B$ck <- B$c * B$k
B$tck <- B$t * B$c * B$k
B <- as.matrix(B)