I have 7 pairs of variables: i.e.
["F1", "R1"] ["F2", "R2"]["F3", "R3"]["F4", "R4"]["F5", "R5"]["F6", "R6"]["F7", "R7"]
And would like generate vectors of 7 variables, where each variable is sampled from each group.
The aim is to generate an ergodic sequence of vectors (in this cases, would be 2^7 = 128 possibilities.
Expected results:
[,1] [,2] [,3] [,4] [,5] [,6] [,7]
[1,] 'F1' 'F2' 'F3' 'F4' 'F5' 'F6' 'F7'
[2,] 'F1' 'F2' 'F3' 'F4' 'F5' 'F6' 'R7'
[3,] 'F1' 'F2' 'F3' 'F4' 'F5' 'R6' 'F7'
[4,] 'F1' 'F2' 'F3' 'F4' 'F5' 'R6' 'R7'
[5,] 'F1' 'F2' 'F3' 'F4' 'R5' 'F6' 'F7'
[6,] 'F1' 'F2' 'F3' 'F4' 'R5' 'F6' 'R7'
...
You can fill a matrix with a single for-loop. You just iterate through each column and fill them by repeating the pairs with the rep function. I have parametrized the code so that the number of pairs can vary:
pairs <- list(c("F1", "R1"), c("F2", "R2"), c("F3", "R3"), c("F4", "R4"),
c("F5", "R5"), c("F6", "R6"), c("F7", "R7"))
dimension <- 7
mat <- matrix(0,2^dimension, dimension)
for(i in 1:dimension){
mat[,i] <- rep(pairs[[i]], each= 2^(dimension-i))
}