A = magic(5)
A = A(:,1:3)
[Q,R] = gs(A)
Q'*Q
ans-eye(3)
Q*R - A
[Q,R]=qr(A,0)
[Q,R]=qr(A)
N = 40;;
N = 400;
x = linspace(-1,1,N+1)';
A = [ x.^0 x.^1 x.^2 x.^3 x.^4 ];
[Q,R]=qr(A,0);
plot(x,Q)