Design matrices of period balanced incomplete block designs

This function returns the ‘design’ matrix of incomplete block designs described by Chow & Liu. The design matrices were recoded 1=R, 2=T1, 3=T2, ...

bib.CL(trt, p)

Arguments

trt

Number of treatments (3 to 5).

p

Number of periods (2 to trt-1).

Value

Matrix containing the sequences in rows and periods in columns.
The entry (i, j) of the matrix corresponds to the treatment or dose (index) a subject within i-th sequence gets in the j-th period.

Author

D. Labes

References

Chow SC, Liu JP. Design and Analysis of Bioavailability and Bioequivalence Studies. Boca Raton: CRC Press; 3^rd edition 2009. Chapter 2.6.

Examples

# 4 treatments/doses, 3 periods
bib.CL(4, 3)
#>      [,1] [,2] [,3]
#> [1,]    2    3    4
#> [2,]    3    4    1
#> [3,]    4    1    2
#> [4,]    1    2    3
# gives 4 sequences
# to see this in Chow & Liu's coding
tmt <- c("R", "T1", "T2", "T3")
matrix(tmt[bib.CL(4, 3)], ncol=3)
#>      [,1] [,2] [,3]
#> [1,] "T1" "T2" "T3"
#> [2,] "T2" "T3" "R" 
#> [3,] "T3" "R"  "T1"
#> [4,] "R"  "T1" "T2"