Combinations of the rows of matrices

I am trying to find all possible combinations of matrices a1-a3.

a1 = [1 2 3; 4 5 6];
a2 = [7 8; 9 10];
a3 = [11; 12];

I want the resulting matrix.

[1 2 3 7 8 11;
1 2 3 9 10 11;
1 2 3 7 8 12;
1 2 3 9 10 12;
4 5 6 7 8 11;
4 5 6 9 10 11;
4 5 6 7 8 12;
4 5 6 9 10 12]

Answer 1

[James Tursa]

A slightly different order for the rows than you have listed, but contains the same content:

[X Y Z] = meshgrid(1:size(a1,1),1:size(a2,1),1:size(a3,1));
result = [a1(X(:),:) a2(Y(:),:) a3(Z(:),:)];