What is created from matrix[n,k] ns=rep_matrix(0,n,k)?

matrix[n,k] ns=rep_matrix(0,n,k)

ns would be a matrix full of 0s with n rows and k columns:

yes i saw that, will not be a n by k array n consisting of copies of matrix nxk with 0 ?

The doc at the link above says

matrix rep_matrix(real x, int m, int n)
Return the m by n matrix consisting of copies of x.

so I think it should just return a matrix filled will copies of x (which is your case is just the real number 0).

what is the difference of this: matrix [n, k] ns = rep_matrix (0, n, k) from this matrix [n, k] rep_matrix (0, n, k) i.e without “ns” what returns?

An error I think. You need the ns here (or any other name, it doesn’t have to be ns) because that’s the name of the variable that the matrix is assigned to. So this line

matrix [n, k] ns = rep_matrix (0, n, k) 

tells Stan to create an n by k matrix with the name ns, so that later you can refer to this matrix just by ns.

  1. you are right! So, it does not create a list (array>2-dimensional?) right?
  2. The "matrix[n,k] x[p] " what creates?
    thanks a lot for your time
  1. Yeah just a single matrix

  2. matrix[n,k] x[p] would create an array containing p matrices, each of which has dimensions n by k.

thank you so much :)

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