#4.2.2 Cleaning materials Example
x<-matrix(c(
1,	2,	3,	4,	NA,   	NA,   	NA,   	NA,	NA,	NA,		
1,	3,	NA,	NA,   	2,	4,   	NA,   	NA,	NA,	NA,	
3,	NA,	4,	NA,	NA,	NA,	2,	1,	NA,	NA,
4,	NA,	NA,	3,	NA,	NA,	NA,	NA,	1,	2,
2,	NA,	NA,	NA,	3,	NA,	1,	NA,	4,	NA,
3,	NA,	NA,	NA,	NA,	4,	NA,	1,	NA,	2,
NA,	2,	1,	NA,	NA,	4,	NA,	NA,	3,	NA,
NA,	2,	NA,	4,	NA,	NA,	3,	NA,	NA,	1,
NA,	1,	NA,	NA,	3,	NA,	NA,	4,	NA,	2,
NA,	3,	NA,	NA,	NA,	NA,	2,	4,	1,	NA,
NA,	NA,	1,	NA,	4,	NA,	NA,	NA,	3,	2,
NA,	NA,	1,	NA,	NA,	2,	4,	NA,	NA,	3,
NA,	NA,	1,	3,	2,	NA,	NA,	4,	NA,	NA,
NA,	NA,	NA,	4,	2,	3,	1,	NA,	NA,	NA,
NA,	NA,	NA,	4,	NA,	2,	NA,	3,	1,	NA,
3,	1,	2,	4,	NA,	NA,	NA,	NA,	NA,	NA,
1,	2,	NA,	NA,	3,	4,	NA,	NA,	NA,	NA,
2,	NA,	4,	NA,	NA,	NA,	3,	1,	NA,	NA,
3,	NA,	NA,	4,	NA,	NA,	NA,	NA,	1,	2,
1,	NA,	NA,	NA,	3,	NA,	2,	NA,	4,	NA,
3,	NA,	NA,	NA,	NA,	4,	NA,	2,	NA,	1,
NA,	1,	3,	NA,	NA,	4,	NA,	NA,	2,	NA,
NA,	1,	NA,	4,	NA,	NA,	3,	NA,	NA,	2,
NA,	1,	NA,	NA,	2,	NA,	NA,	4,	NA,	3,
NA,	1,	NA,	NA,	NA,	NA,	4,	3,	2,	NA,
NA,	NA,	1,	NA,	3,	NA,	NA,	NA,	2,	4,
NA,	NA,	1,	NA,	NA,	2,	4,	NA,	NA,	3,
NA,	NA,	1,	3,	2,	NA,	NA,	4,	NA,	NA,
NA,	NA,	NA,	4,	2,	3,	1,	NA,	NA,	NA,
NA,	NA,	NA,	4,	NA,	1,	NA,	2,	3,	NA),ncol=10,byrow=T)
colnames(x)<-c("A","B","C","D","E","F","G","H","I","J")

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