Diseño cuadrado latino: Asignando tratamientos al azar usando R

#Cargado función "latin" a R
source("C:/Users/Administrator/Desktop/latin.R")

# verificando contenido de "latin"
latin     

function (n, nrand = 20) 
{
    x = matrix(LETTERS[1:n], n, n)
    x = t(x)
    for (i in 2:n) x[i, ] = x[i, c(i:n, 1:(i - 1))]
    if (nrand > 0) {
        for (i in 1:nrand) {
            x = x[sample(n), ]
            x = x[, sample(n)]
        }
    }
    x
}

# aleatorización de 4 tratamientos 
latin(4)  

     [,1] [,2] [,3] [,4]
[1,] "C"  "B"  "D"  "A" 
[2,] "B"  "A"  "C"  "D" 
[3,] "D"  "C"  "A"  "B" 
[4,] "A"  "D"  "B"  "C" 

# aleatorización de 8 tratamientos 
latin(8)

     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
[1,] "H"  "C"  "B"  "E"  "A"  "F"  "G"  "D" 
[2,] "C"  "F"  "E"  "H"  "D"  "A"  "B"  "G" 
[3,] "D"  "G"  "F"  "A"  "E"  "B"  "C"  "H" 
[4,] "E"  "H"  "G"  "B"  "F"  "C"  "D"  "A" 
[5,] "A"  "D"  "C"  "F"  "B"  "G"  "H"  "E" 
[6,] "F"  "A"  "H"  "C"  "G"  "D"  "E"  "B" 
[7,] "G"  "B"  "A"  "D"  "H"  "E"  "F"  "C" 
[8,] "B"  "E"  "D"  "G"  "C"  "H"  "A"  "F" 

Fuente de función: 

Larget, B. 2007. Latin Square Designs. Department of Botany and of Statistics; University of Wisconsin—Madison. PowerPoint presentation Slide 6. Enlace http://www.stat.wisc.edu/courses/st572-larget/Spring2007/handouts17-4.pdf