Fix bug in SAT terms for upwind operators - Set the appropriate boundary derivatives in respect to choice of upwind discretization of D2 - Distinguish between upwind discretizations e.g upwind+ vs upwind-

function q = convergence(e,h)
    for i = 1:length(e)-1
        q(i) = log(e(i)/e(i+1))/log(h(i+1)/h(i));
    end
end