小编Muh*_*amd的帖子

I have a nested loop as

X <- matrix(c(0.5,0,0,0.75), nrow = 2)
k = nrow(X)

ans1 <- 0
ans2 <- 0
for (aa in 1:k) {
  for (bb in 1:k) {
    for (cc in 1:k) {
      for (dd in 1:k) {
        ans1 = ans1 + (0.45 * X[aa,bb] * X[cc,dd])
        for (xx in 1:k) {
          for (yy in 1:k){ 
            ans2 = ans2 + (1.7*X[aa,bb]*X[xx,yy]*X[cc,dd] + 0.2*X[aa,xx]*X[bb,yy]*X[cc,dd])  
          }
        }
      }
    }
  }
}

But the matrix X which must be a …