Create residual viscosity package +rv and generalize the ResidualViscosity class - Generalize residual viscosity, by passing user-defined flux and calculating the time derivative outside of the update. - Create separate RungekuttaRV specifically using interior RV updates - Separate the artifical dissipation operator from the scheme AdvectionRV1D so that the same scheme can be reused for creating the diff op used by the ResidualViscosity class

function alpha = matrixborrow(A,B)

    function y = neg(x)
        y = min(eig(A-x*B));
    end


    x0 = 1;
    while neg(x0) > -1
        x0 = 2*x0;
    end

    opt = optimset('Display','none');
    alpha = fsolve(@neg, x0,opt);
end