Calculating co-voting within and between groups-CodePudding

I have a square matrix with information on the co-voting behavior between individuals (15x15 in toy example below). The rows and columns of the matrix are arranged according to the groups the individuals belong to (A, B or C). The entries indicate whether or not two individuals voted the same way 50% of the time (possible entries: 1, 0, NaN).

I need to calculate the rate/fraction of co-voting within and between groups. The resulting matrix in the toy example should be a 3x3 matrix with A, B, C on the rows and columns and values ranging from 0 to 1. How can I do this using for loops?

  A A A A A B B B B B C C C C C
A 1 1 1 1 1 1 0 0 0 0 0 1 1 1 0
A 1 1 1 1 1 1 0 0 0 0 0 1 1 1 0
A 1 1 1 1 1 1 0 0 0 0 1 1 1 1 0
A 1 1 1 1 1 1 0 0 0 0 0 1 1 1 0
A 1 1 1 1 1 1 0 0 0 0 0 1 1 1 0
B 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1
B 0 0 0 0 0 1 1 1 1 1 1 0 0 1 1
B 0 0 0 0 0 1 1 1 1 1 1 1 0 1 1
B 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1
B 0 0 0 0 0 1 1 1 1 1 1 0 0 1 1
C 0 0 1 0 0 1 1 1 1 1 1 1 0 0 1
C 1 1 1 1 1 1 0 1 0 0 1 1 1 0 1
C 1 1 1 1 1 1 0 0 0 0 0 1 1 1 0
C 1 1 1 1 1 1 1 1 0 1 0 0 1 1 0
C 0 0 0 0 0 1 1 1 1 1 1 1 0 0 1

CodePudding user response：

If your matrix is called m, you could do

groups <- unique(colnames(m))

res <- matrix(0, 3, 3, dimnames = list(groups, groups))

for(i in groups) {
  for(j in groups) {
    mat <- m[rownames(m) %in% i, colnames(m) %in% j]
    res[rownames(res) %in% i, colnames(res) %in% j] <- sum(mat) / length(mat)
  }
}

res
#>      A    B    C
#> A 1.00 0.20 0.64
#> B 0.20 0.92 0.68
#> C 0.64 0.68 0.60

^{Created on 2022-06-02 by the reprex package (v2.0.1)}

Data taken from question in reproducible format

m <- structure(c(1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 
1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 1L, 
0L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 0L, 1L, 1L, 1L, 1L, 0L, 
1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 1L, 0L, 1L, 
1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 1L, 0L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 
0L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 1L, 1L, 0L, 0L, 0L, 0L, 
0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 
0L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 1L, 
1L, 1L, 1L, 1L, 1L, 0L, 0L, 1L, 1L, 0L, 0L, 1L, 0L, 0L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 0L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 
0L, 0L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 
0L, 0L, 1L, 1L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 1L, 
0L, 0L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 0L, 0L, 1L), dim = c(15L, 15L), dimnames = list(c("A", "A", 
"A", "A", "A", "B", "B", "B", "B", "B", "C", "C", "C", "C", "C"
), c("A", "A", "A", "A", "A", "B", "B", "B", "B", "B", "C", "C", 
"C", "C", "C")))