A = coeffmat(4);
b = rhsmat([0,0,0,0], [20,40,60,80], [50,20,10,0], [20,40,60,80]), pause

s = A \ b;

s = reshape(s, 4, 4)';

S = [(s(1,1) + 20 + 0)/3 0 0 0 0 (s(1,4) + 20 + 0)/3; ...
     [20; 40; 60; 80] s [20; 40; 60; 80]; ...
     (s(4,1) + 80 + 50)/3 50 20 10 0 (s(4,4) + 80 + 0)/3]

surf(S); pause

for j=1:10; view(-20, 10*j); pause; end

view(3)
