Write a function called quadrants that takes as its input argument a scalar integer named n. The function returns Q, a 2n-­‐by-­‐2n matrix. Q consists of four n-­‐by-­‐n submatrices. The elements of the submatrix in the top left corner are all 1s, the elements of the submatrix at the top right are 2s, the elements in the bottom left are 3s, and the elements in the bottom right are 4s.

function Q = quadrants(n)
A(1:n,1:n)=1;
B(1:n,1:n)=2;
C(1:n,1:n)=3;
D(1:n,1:n)=4;
Q = [A B;C D];