---

A = [1 2; 3 4]
B = [5 6; 7 8]
C = [9 10; 11 12]
D = [13 14; 15 16]

K = [A B; C D]

S = [5 0; 6 4]
a = [8; 7]
b = [-6 3]

M = [S a; b 3.5]

K1 = K(1:2, 3:4)
K2 = K(3:4, 1:2)

m = M(3,:)

K(1,:) = []
K(:,3) = []

A0 = zeros(3,4)
B0 = zeros(3)

A1 = ones(3,4)
B1 = ones(3)

A = rand(3,4)
B = rand(3)

r = rand(1,7)

d = [1;2;3;4]
D = diag(d)

M = [-2*eye(5) 5*ones(5); 2*ones(5) eye(5)]

save M.txt M -ascii

G = 4*eye(7) + diag(ones(1,6),1) + diag(ones(1,6),-1)

save G.txt G -ascii