#4.6.1 Ice Cream (Off Flavour) Example 
x<-matrix(c(
6,	1,	1,	2,	NA,	NA,
6,	NA,	NA,	1,	3,	3,
NA,	4,	2,	NA,	5,	2,
7,	2,	3,	NA,	2,	NA,
3,	5,	NA,	1,	NA,	1,
NA,	NA,	1,	1,	3,	2,
7,	4,	4,	NA,	NA,	3,
2,	NA,	1,	1,	1,	NA,
NA,	2,	NA,	2,	2,	3,
4,	2,	NA,	2,	5,	NA,
5,	NA,	3,	NA,	1,	1,
NA,	3,	2,	1,	NA,	2,
4,	2,	NA,	NA,	1,	1,
5,	NA,	2,	2,	NA,	1,
NA,	2,	4,	5,	3,	NA),ncol=6,byrow=T)
colnames(x)<-c("A","B","C","D","E","F")

xtotab(x)
U(x)
BlockAnalysis(x)