Hopf_eq_DGRK Solving Hopf Equation using DGRK Requirements Polynomial.jl LegendrePolynomials.jl Our problem $$ \begin{cases} \frac{\partial U}{\partial t} + U \frac{\partial U}{\partial x} = 0, T\in [0, 2], x \in [-3, 3]; \\ U(x, 0) = \frac{1}{1 + x^2} \end{cases} $$