how can i store all simulation results from gibbs sampling VERTICALLY?

for example : for i=1:3 b=n*ones(3) end the result will be [3 3 3;3 3 3;3 3 3] BUT i want to save the hole result as [1 1 1;1 1 1;1 1 1;2 2 2;2 2 2;2 2 2;3 3 3;3 3 3;3 3 3] How can i do it???? I'v got the following answer

For i=1:3

    a{i}=i*ones(3);

end

b=cell2mat(a)

the result will be [111222333;111222333;111222333] BUT, the result i want is to be as [111;111;111;222;222;222;333;333;333] is it possible??

Answer 1

[Muruganandham Subramanian]

try this:

for i=1:3
      a{i}=i*ones(3);
      d(:,:,i)=a{i};
end

Answer 2

[Andrei Bobrov]

b = kron((1:3)',ones(3));