R：将矩阵与r中的另一个矩阵映射

Question

I found a same question in map a matrix with another matrix . But, that is in Matlab. If I want to map a matrix with another matrix in R, How can I easily get without using a loop. For example, I have following matrices,

A = [ 1 4 3
      2 3 4 
      4 3 1 
      4 5 5 
      1 2 1]

 B = [3 3 2
      2 0 1
      1 1 5
      4 1 3
      5 2 0]

My mapping should be as given bellow;

  R = [1 4 3
      2 3 4
      4 3 5
      4 1 3
      5 2 0]

The result R will take the values from A starting from [1,1] to [3,2]. Then remaining values are from B starting from [3,3] to [5,3].

Answer 1

As simple as:

R <- t(A)
R[9:15] <- t(B)[9:15]
t(R)

  [,1] [,2] [,3] [1,] 1 4 3 [2,] 2 3 4 [3,] 4 3 5 [4,] 4 1 3 [5,] 5 2 0 

Sample data

A <- matrix(c(1,4,3,2,3,4,4,3,1,4,5,5,1,2,1), nrow = 5, ncol = 3, byrow = TRUE)
B <- matrix(c(3,3,2,2,0,1,1,1,5,4,1,3,5,2,0), nrow = 5, ncol = 3, byrow = TRUE)

Answer 2

到Djack的做法有一点不同，我使用的matrix与byrow = T ，和索引的原始矩阵：

matrix(c(t(A)[1:8], t(B)[9:15]), byrow = T, ncol = 3)