how to replicate an array

Question

I want to make a function like this

>> matdup([1 2],3,4)            %or any other input that user wish to enter
ans= 

 1     2     1     2     1     2         


        

Answer 1

Try kron:

matdup = @(x,m,n) kron(ones(m,n),x)

Demonstration:

>> A = [5 6 7];
>> out = matdup(A,3,2)
out =
     5     6     7     5     6     7
     5     6     7     5     6     7
     5     6     7     5     6     7

---

Note that you can switch the inputs to kron to effectively replicate elements rather than the whole matrix:

repel = @(x,m,n) kron(x,ones(m,n));

Demonstration:

>> A = [5 6 7];
>> out = repel(A,3,2)
out =
     5     5     6     6     7     7
     5     5     6     6     7     7
     5     5     6     6     7     7