When I output 'mat', it works as expected, with mat giving the whole list of matrices and mat[1], mat[2] and mat[3] giving the first second and third elements, namely 4x4 matrices with all entries equal to 1, 2 and 3 respectively.
However when I try to add a new element or change an existing one, I get an error, and instead of adding a 4x4 matrix to the list, it just adds a regular number.
How would I add a new matrix to the list? I am also open to using alternatives to list(). I am relatively new to R and I'd always used x = c(), but that doesn't seem to work for matrices either. Thanks in advance.
Input:
mat = list( matrix (c(1), nrow = 4, ncol = 4, byrow = TRUE),
matrix (c(2), nrow = 4, ncol = 4, byrow = TRUE),
matrix (c(3), nrow = 4, ncol = 4, byrow = TRUE) )
mat
mat[2]
mat[1] = matrix(c(0), nrow = 4, ncol = 4, byrow = TRUE)
mat[4] = matrix(c(4), nrow = 4, ncol = 4, byrow = TRUE)
mat
Output:
> mat = list( matrix (c(1), nrow = 4, ncol = 4, byrow = TRUE),
+ matrix (c(2), nrow = 4, ncol = 4, byrow = TRUE),
+ matrix (c(3), nrow = 4, ncol = 4, byrow = TRUE) )
> mat
[[1]]
[,1] [,2] [,3] [,4]
[1,] 1 1 1 1
[2,] 1 1 1 1
[3,] 1 1 1 1
[4,] 1 1 1 1
[[2]]
[,1] [,2] [,3] [,4]
[1,] 2 2 2 2
[2,] 2 2 2 2
[3,] 2 2 2 2
[4,] 2 2 2 2
[[3]]
[,1] [,2] [,3] [,4]
[1,] 3 3 3 3
[2,] 3 3 3 3
[3,] 3 3 3 3
[4,] 3 3 3 3
> mat[2]
[[1]]
[,1] [,2] [,3] [,4]
[1,] 2 2 2 2
[2,] 2 2 2 2
[3,] 2 2 2 2
[4,] 2 2 2 2
> mat[1] = matrix(c(0), nrow = 4, ncol = 4, byrow = TRUE)
Warning message:
In mat[1] = matrix(c(0), nrow = 4, ncol = 4, byrow = TRUE) :
number of items to replace is not a multiple of replacement length
> mat[4] = matrix(c(4), nrow = 4, ncol = 4, byrow = TRUE)
Warning message:
In mat[4] = matrix(c(4), nrow = 4, ncol = 4, byrow = TRUE) :
number of items to replace is not a multiple of replacement length
> mat
[[1]]
[1] 0
[[2]]
[,1] [,2] [,3] [,4]
[1,] 2 2 2 2
[2,] 2 2 2 2
[3,] 2 2 2 2
[4,] 2 2 2 2
[[3]]
[,1] [,2] [,3] [,4]
[1,] 3 3 3 3
[2,] 3 3 3 3
[3,] 3 3 3 3
[4,] 3 3 3 3
[[4]]
[1] 4
