Setting up a 3D matrix in R and accessing certain elements

Question

I am trying to set up a 3D matrix in R. I guess this is an easy one. However, I didn\'t find a solution so far. Let\'s say we want to create a 365x6x4 matrix. Also crucial form

Answer 1

A matrix is a special 2-dimensional case of an array. (Quoting from the help for ?matrix).

So, you need array:

x <- array(rep(1, 365*5*4), dim=c(365, 5, 4))
str(x)
num [1:365, 1:5, 1:4] 1 1 1 1 1 1 1 1 1 1 ...

Set a specific value:

x[305, 5, 2] <- 204

Print one slice:

x[305, , ]
     [,1] [,2] [,3] [,4]
[1,]    1    1    1    1
[2,]    1    1    1    1
[3,]    1    1    1    1
[4,]    1    1    1    1
[5,]    1  204    1    1