Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php SIAM J. SCI. COMPUT. Vol. 35, No. 1, pp. A122–A149 c 2013 Society for Industrial and Applied Mathematics ALTERNATING EVOLUTION SCHEMES FOR HAMILTON–JACOBI EQUATIONS∗ HAILIANG LIU† , MICHAEL POLLACK† , AND HASEENA SARAN† Abstract. In this work, we propose a high-resolution alternating evolution (AE) scheme to solve Hamilton–Jacobi equations. The construction of the AE scheme is based on an alternating evolution system of the Hamilton–Jacobi equation, following the idea previously developed for hyperbolic conservation laws. A semidiscrete scheme derives directly from a sampling of this system on alternating grids. Higher order accuracy is achieved by a combination of high order nonoscillatory polynomial reconstruction from the obtained grid values and a time discretization with matching accuracy. Local AE schemes are made possible by choosing the scale parameter to reflect the local distribution of waves. The AE schemes have the advantage of easy formulation and implementation and efficient computation of the solution. For the first local AE scheme and the second order local AE scheme with a limiter, we prove the numerical stability in the sense of satisfying the maximum principle. Numerical experiments for a set of Hamilton–Jacobi equations are presented to demonstrate both accuracy and capacity of these AE schemes. Key words. alternating evolution, Hamilton–Jacobi equations, viscosity solution AMS subject classifications. 65M06, 65M12, 35L02 DOI. 10.1137/120862806 1. Introduction. In this paper, we develop a new alternating evolution (AE) method to solve time-dependent Hamilton–Jacobi (HJ) equations. We describe the designing principle of our new AE scheme through the following form: φt + H(x, ∇x φ) = 0, φ(x, 0) = φ0 (x), x ∈ Rd , t > 0. Here, d is the space dimension, the unknown φ is scalar, and H : Rd → R1 is a nonlinear Hamiltonian. The HJ equation arises in many applications, ranging from geometrical optics to differential games. These nonlinear equations typically develop discontinuous derivatives even with smooth initial conditions, the solutions of which are nonunique. In this paper, we are only interested in the viscosity solution [7, 6, 29], which is the unique physically relevant solution in some important applications. The difficulty encountered for the satisfactory approximation of the exact solutions of these equations lies in the presence of discontinuities in the solution derivatives. An important class of finite difference methods for computing the viscosity solution is the class of monotone schemes introduced by Crandall and Lions [8]. Unfortunately, monotone schemes are at most first order accurate. The need for devising more accurate numerical methods for HJ equations has prompted the abundant research in this area in the last two decades, including essentially nonoscillatory (ENO) or weighted ENO (WENO) finite difference schemes (see, e.g., [24, 25, 13, 17, 28, 31]) and central or central-upwind finite difference schemes (see, e.g., [19, 16, 15, 4, 2, 3]), as well as discontinuous Galerkin methods [12, 5, 30, 22]. ∗ Submitted to the journal’s Methods and Algorithms for Scientific Computing section January 19, 2012; accepted for publication (in revised form) November 26, 2012; published electronically January 8, 2013. This research was partially supported by the National Science Foundation under grant DMS 09-07963. http://www.siam.org/journals/sisc/35-1/86280.html † Mathematics Department, Iowa State University, Ames, IA 50011 (hliu@iastate.edu, mpollack@ iastate.edu, haseena.saran@gmail.edu). A122 Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A123 The preliminary goal of this paper is to design high order finite difference schemes for HJ equations by following the alternating evolution framework introduced in [21] for hyperbolic conservation laws; see local AE schemes developed by Saran and Liu [26]. The global AE scheme [21] shares similar features to central schemes by Y. Liu [23] using overlapping cells. In such a framework, the general setting is to refine the original PDE by an AE system which involves two representatives: {u, v}. In the evolution of u, terms involving spatial derivatives are replaced by v’s derivatives and augmented by an additional relaxation term (v − u)/, which serves to communicate the two representatives. The AE system for scalar hyperbolic conservation laws was shown in [21] to be capable of capturing the exact solution when initially both representatives are chosen as the given initial data. Such a feature allows for a sampling of two representatives over alternating grids. Using this alternating system as a “building base,” we apply standard approximation techniques to the AE system: high order accuracy is achieved by a combination of high order nonoscillatory polynomial reconstruction in space and an ODE solver in time with matching accuracy, following those implemented for hyperbolic conservation laws in [26]. Preliminary results on AE schemes for HJ equations were reported in the third author’s thesis [1]. For Hamilton–Jacobi equations, we consider the following alternating evolution system: 1 (v − u), 1 vt + H(x, ∇x u) = (u − v). ut + H(x, ∇x v) = Here, > 0 is a scale parameter of the user’s choice. At t = 0, we take the initial data u0 (x) = v0 (x) = φ0 (x). We sample the above system over alternating grids when performing the spatial discretization, leading to a class of high-resolution semidiscrete AE schemes. One of the main differences between the formulation of AE schemes for HJ equations and that for conservation laws is that here we use grid point values instead of cell averages. The semidiscrete schemes thus obtained have the form 1 1 d Φα + H(xα , ∇x pα [Φ](xα )) + Φα = pα [Φ](xα ), dt where pα [Φ](x) is the polynomial reconstruction based on grid values of Φ in the domain centered at xα . The scale parameter and the time step size Δt are chosen to stabilize the time discretization. In the one-dimensional case, the fully discrete AE scheme of first order becomes Φnk+1 − Φnk−1 Δt Δt 1 n n+1 n n (Φ + Φk−1 ) − H xk , Φk = 1 − Φk + , ≥ Δt, 2 k+1 2Δx which when = Δt is taken reduces to the celebrated Lax–Friedrichs scheme Φnk+1 − Φnk−1 1 n n+1 n . Φk = (Φk+1 + Φk−1 ) − H xk , 2 2Δx Thus the class of AE schemes can be viewed as a higher order extension of the Lax– Friedrichs scheme. To put our study in the proper perspective, we recall that the success of existing finite difference schemes for HJ equations is due to two factors: the local enforcement Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A124 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN of the equation in question and the nonoscillatory piecewise polynomial interpolation from evolved grid values. The present AE scheme differs from the existing ones in the local enforcement. The ENO/WENO type schemes [24, 25, 13, 17, 28, 31] are based mainly on some local refinement of HJ equations by − ut + Ĥ(x, φ+ x , φx ) = 0, where Ĥ is the numerical Hamiltonian which needs to be carefully chosen to ensure the viscosity solution is captured when φx becomes discontinuous. Instead, the central type schemes [20, 19, 16, 15, 4, 2, 3] choose to evolve the constructed polynomials in smooth regions such that the Taylor expansion may be used in the scheme derivation. Effort has been made to extend these ideas toward some discontinuous Galerkin methods such as in [12, 5, 30, 22]; however, these extensions either are restricted or involve some further local refinement. The scheme we design here is different in that it is based on alternatively sampling the AE system with spatial accuracy enhanced by interlaced local interpolations. The procedure discussed in this paper opens a new door to deriving robust finite difference schemes for HJ equations. Also the semidiscrete scheme thus obtained offers an economic approach for achieving a matching accuracy in time. Another attractive feature of the AE scheme is the amount of the leverage in the choice of . Indeed, different choices of the scale parameter in such a procedure yield different AE schemes such as local and global AE schemes. For the polynomial construction, we use standard polynomial interpolation with ENO choice of stencils or appropriate limiters to ensure the computed solution is the viscosity solution. Extension of the AE idea to a discontinuous Galerkin setting is under investigation. It should be noted that even though our AE schemes are derived based on sampling the AE system, we do not solve the system directly. The AE system simply provides a systematic way for developing numerical schemes of both semidiscrete and fully discrete form for the original problem, instead of as an approximation system at the continuous level. The article is organized as follows. In section 2, we formulate the AE method for one-dimensional HJ equations. We then give a rigorous proof of L∞ stability by the AE method of both first and second order in section 3. Extensions to the multidimensional case are given in section 4, including stability for the AE method of first and second order. In section 5, we show numerical results, which include both one- and two-dimensional problems. The results illustrate accuracy, efficiency, and high resolution near kinks. Section 6 ends this paper with our concluding remarks. 2. Alternating evolution methods. Our numerical schemes for HJ equations consist of a semidiscrete formulation based on sampling of the AE system on alternating grids and a fully discrete version by further using an appropriate Runge–Kutta solver. To illustrate, we start with the one-dimensional HJ equation of the form φt + H(x, φx ) = 0. The “building base” is the following AE system: (2.1) (2.2) 1 (v − u), 1 vt + H(x, ux ) = (u − v). ut + H(x, vx ) = Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A125 2.1. Semidiscrete formulation. Consider a uniform discretization {xk , k ∈ Z} with grid size Δx. We sample the AE approximate system (2.1)–(2.2) at the even and odd grid points, respectively, to obtain 1 1 d u2i (t) = − u2i + L[v](x2i , t), dt d 1 1 v2i+1 (t) = − v2i+1 + L[u](x2i+1 , t), dt where L[Φ](x, t) = Φ − H(x, Φx ). We assume that we have computed the solution at t, denoted by uk , k = 2i, Φk = k = 2i + 1. vk , To update each grid value Φk with a high order of accuracy, we construct a nonoscillatory polynomial approximation pk [Φ](x) using grid point values {xk±i } for some i = 1, 2, . . . . The numerical approximation for L is then realized by L[pk [Φ]](xk , t), which leads to the following semidiscrete scheme: d 1 1 Φk (t) = − Φk + Lk [Φ](t), dt (2.3) where Lk [Φ](t) = pk [Φ](xk ) − H (xk , ∂x pk [Φ](xk )) . The fully discrete scheme follows from applying an appropriate Runge–Kutta solver to (2.3). For a computational domain [a, b] with x0 = a, xN = b, and Δx = (b − a)/N , we summarize the algorithm as follows. Algorithm 2.1. 1. Initialization: at any node xk , compute the initial data as Φ0k = φ0 (xk ), k = 0, 1, . . . , N . 2. Polynomial construction: from {Φk±i } construct (r + 1)th order nonoscillatory polynomial pk [Φ](x) and rth order polynomial ∂x pk [Φ](x) on Ik , k = 1, 2, . . . , N , then sample at xk to get Lk [Φ] = pk [Φ](xk ) − H (xk , ∂x pk [Φ](xk )) , k = 1, 2, . . . , N. 3. Evolution: obtain Φn+1 from Φn by the following TVD Runge–Kutta type procedure [25]: (l) Φk = (0) Φk = l−1 (i) αli Φk − i=0 (n) Φk , βli (i) Φk + Lk [Φ(i) ] , l = 1, . . . , r, (r) Φn+1 = Φk . k In the AE schemes up to the third order, is chosen such that the stability condition, Δt ≤ ≤ Q Δx , max |Hp (x, p)| is satisfied. The choice of Q depends on the order of the scheme; see (3.1) and (3.5) in section 3. Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A126 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN 2.2. Fully discrete AE schemes. We now present AE schemes of the first, second, and third order for HJ equations and then discuss advantages of using a local parameter = nj . 2.2.1. First order scheme. We start with a linear interpolant at nodes {xk−1 , xk+1 }, p1k [Φ](x) = Φk−1 + sk (x − xk−1 ), sk = Φk+1 − Φk−1 , 2Δx and sample at xk , p1k [Φ](xk ) = Φk+1 + Φk−1 2 and ∂x p1k [Φ](xk ) = sk = Φk+1 − Φk−1 . 2Δx This, when combined with a forward Euler in time discretization, gives the first order numerical scheme Φnk+1 − Φnk−1 1 n n n (Φ = (1 − κ)Φ + κ + Φ ) − H x , (2.4) Φn+1 , k k k−1 k 2 k+1 2Δx Δx where κ := Δt < 1. When ≤ max |Hp (·)| , this forms a class of monotone schemes, with the celebrated Lax–Friedrichs scheme being a special case of κ = 1. 2.2.2. Second order scheme. A second order continuous, piecewise quadratic reconstruction gives p2k [Φ](x) = Φk−1 + sk (x − xk−1 ) + sk (x − xk−1 )(x − xk+1 ), 2 where sk is the first numerical derivative defined as before and sk is an approximation to the exact second derivative φxx . We then obtain p2k [Φ](xk ) = s Φk+1 + Φk−1 − k (Δx)2 2 2 and ∂x p2k [Φ](xk ) = sk = Φk+1 − Φk−1 , 2Δx which when combined with the second order Runge–Kutta method (Heun’s method) gives Φ∗k = (1 − κ)Φnk + κLk [Φn ], 1−κ 1 n κ n+1 Φk = Φk + Φ∗k + Lk [Φ∗ ], 2 2 2 (2.5) (2.6) where (2.7) Lk [Φ] = 1 n (Δx)2 Φk+1 − Φk−1 (Φk−1 + Φnk+1 ) − sk − H xk , . 2 2 2Δx The nonoscillatory nature of the scheme is realized by the choice of sk . We follow the ENO interpolation technique [11, 25] to select the “smoother” polynomial candidates. For a second order approximation, we choose from two quadratic interpolants which use {xk−3 , xk−1 , xk+1 } and {xk−1 , xk+1 , xk+3 }, respectively, following sk+2 − sk sk − sk−2 , sk = M (2.8) , 2Δx 2Δx where M(a, b) = a if |a| ≤ |b| and b if |b| < |a|. Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A127 2.2.3. Third order scheme. We formulate the third order scheme by using a cubic polynomial interpolant with the ENO selection. For x∗ = xk−3 or x∗ = xk+3 determined through the ENO selection (2.8), a cubic polynomial interpolant is given as p3k [Φ](x) = Φk−1 + sk (x − xk−1 ) + + sk (x − xk−1 )(x − xk+1 ) 2 sk (x − xk−1 )(x − xk+1 )(x − x∗ ), 6 where the ENO selection requires that sk+2 − sk sk − sk−2 , sk = M (2.9) . 2Δx 2Δx The obtained polynomial and its derivative when evaluated at xk give 1 s s (Φk+1 + Φk−1 ) − k (Δx)2 − k (Δx)2 (xk − x∗ ), 2 2 6 s − Φ Φ k+1 k−1 − k (Δx)2 , ∂x p3k [Φ](xk ) = 2Δx 6 p3k [Φ](xk ) = which when combined with the third order Runge–Kutta method gives (1) Φk = (1 − κ)Φnk + κLk [Φn ], 3 1 (2) (1) Φk = Φnk + (1 − κ) Φk + 4 4 1 2 (2) Φn+1 = Φnk + (1 − κ) Φk + k 3 3 1 κLk [Φ(1) ], 4 2 κLk [Φ(2) ] 3 with Lk [Φ] = 1 n s s (Φk−1 + Φnk+1 ) − k (Δx)2 − k (Δx)2 (xk − x∗ ) 2 2 6 s − H xk , sk − k (Δx)2 . 6 Remark 2.2. The above ENO selection procedure can be applied hierarchically to any higher order polynomial approximation. Also, to make stencils more compact, mixed grids {Φk±i } instead of even or odd grids {Φk+2i−1 } may be used in the polynomial construction. 2.3. Local AE schemes. In practice, it is preferred to use local AE schemes, in which local speeds instead of global speeds are explored in the scheme formulation for . The notation Mk is used to denote the range Mk = min ∂x pk [Φ](x), max ∂x pk [Φ](x) , Ik Ik where Ik = [xk−1 , xk+1 ]. Depending on the way k is defined, we can formulate two local AE schemes: Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. A128 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php 1. Local AE1 scheme. We choose k such that k ≤ Q (2.10) Δx . max |Hp (x, p)| p∈Mk ,x∈Ik 2. Local AE2 scheme. We choose k such that k ≤ Q (2.11) maxx∈Ik 1 |Mk | Δx |Hp (x, p)| dp . Mk In both cases we want the time step Δt < min k , k since the stability conditions require that κ = Δt k < 1. Q is a factor that is dependent on the order of the scheme and the stability conditions to be presented in section 3 provide the range of values Q can take. 3. Stability analysis. In this section we show that the first and second order schemes are nonoscillatory in the sense of satisfying the maximum principle. Let Φn be a computed solution and |Φn |∞ = maxk {|Φnk |} define the standard l∞ norm. For simplicity we present the stability results only for the case H(x, p) = H(p). We first prove stability for global AE schemes. The proofs for local schemes are similar; only needs to be considered as defined locally instead of globally. Theorem 3.1. Let Φ be computed from the first order AE scheme (2.4) for the HJ equation φt + H(φx ) = 0. If max |H (·)| ≤ 1 Δx (3.1) and Δt < , hold, then min Φnk ≤ Φn+1 − H(0)Δt ≤ max Φnk , k (3.2) k k n ∈ N. Proof. The scheme (2.4) can be written as Φn+1 k When have = (1 − Δx κ)Φnk + κLk [Φ], Φn + Φnk+1 − H Lk [Φ] = k−1 2 Φnk+1 − Φnk−1 2Δx . max |H | ≤ 1, Lk [Φ] becomes nondecreasing in both Φk−1 and Φk+1 , we min Φk − H(0) = Lk [min Φk ] ≤ Lk [Φ] ≤ Lk [max Φk ] = max Φk − H(0). Note that for κ < 1, Φn+1 is a convex combination of Φnk and Lk [Φn ]; therefore the k claimed estimate (3.2) follows. Without loss of generality we can assume H(0) = 0 (this can be made so by a transform of φ − H(0)t in the original equation), so that the estimate (3.2) becomes |Φn+1 |∞ ≤ |Φn |∞ . Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A129 Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php ENO from (2.8) MM from (3.3) MM from (3.4) 0.55 0.5 0.45 0.4 0.35 0.3 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 Fig. 1. Comparison of three different approximations for sk , ENO from (2.8) and MM from (3.3) and (3.4), when second order scheme is applied to Example 5.3 with T = 1, N = 80, Δt = 0.9. Such an estimate for second order AE schemes still holds if some stricter limiter on numerical derivatives sk is taken. As is known, an alternative limiter for the second order scheme is the minmod limiter sk+1 − sk sk − sk−1 sk = MM (3.3) , . Δx Δx Here M M denotes the minmod nonlinear limiter ⎧ ⎨ minj {xj } maxj {xj } MM{x1 , x2 , . . . } = ⎩ 0 if xj > 0 ∀j, if xj < 0 ∀j, otherwise. We modify this limiter to obtain (3.4) sk = 1 (MM{sk+1 , sk } − MM{sk , sk−1 }) . Δx A comparison of the ENO selection and the minmod limiters from (3.3) and (3.4) is shown in Figure 1 for Example 5.3. As one can see, the ENO approximation provides the most accurate results for the reference solution. In order to establish the stability result, sk will be chosen as the stricter limiter from (3.4). Theorem 3.2. Let Φn be computed from the second order AE scheme (2.5) for HJ equations with H(0) = 0 and with slopes sk defined as in (3.4). If (3.5) 1 max |H (·)| ≤ Δx 2 and Δt < hold, then (3.6) |Φn+1 |∞ ≤ |Φn |∞ , n ∈ N. Proof. It suffices to show that (3.7) |L[Φn ]|∞ ≤ |Φn |∞ , Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. A130 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php so that when κ < 1, |Φ∗ |∞ ≤ (1 − κ)|Φn |∞ + κ|Φn |∞ ≤ |Φn |∞ . Then, from (2.6), it follows that |Φ n+1 |∞ 1 ≤ |Φn |∞ + 2 1−κ 2 |Φ∗ |∞ + κ |L[Φ∗ ]|∞ 2 from which the maximum principle as claimed in (3.6) follows. We now prove (3.7). From (2.7) we have that n Φk+1 − Φnk−1 1 s Lk [Φn ] = (Φnk+1 + Φnk−1 ) − k (Δx)2 − H . 2 2 2Δx Notice that H(0) = 0 and define ⎧ sk ⎪ ⎨ −(Δx)2 Φnk+1 − Φnk−1 βkn := ⎪ ⎩ 0 if Φnk+1 = Φnk−1 , if Φnk+1 = Φnk−1 . Hence, (3.8) 1 n βn (Φk+1 + Φnk−1 ) + k (Φnk+1 − Φnk−1 ) − H (·)(Φnk+1 − Φnk−1 ) 2 2 2Δx 1 1 1 + βkn − H (·) Φnk+1 + 1 − βkn + H (·) Φnk−1 , = 2 Δx 2 Δx Lk [Φn ] = where (·) is an unspecified intermediate value between 0 and sk . The minmod property on the second numerical derivative sk leads to sk ≤ 1 |sk | = |Φn − Φnk−1 |, Δx 2(Δx)2 k+1 max |H | ≤ 12 ensures that all and hence βkn ≤ 12 . This together with the condition Δx the coefficients on the right of (3.8) are nonnegative and we can take the maximum norm to obtain |L[Φn ]|∞ ≤ |Φn |∞ , as claimed. 4. The multidimensional case. By similar procedures we can construct AE schemes for multidimensional HJ equations: φt + H(x, ∇x φ) = 0, x ∈ Rd . We start with the AE formulation (4.1) 1 1 ut + u = v − H(x, ∇x v). Let {xα } be uniformly distributed grids in Rd . Consider Iα to be a hypercube centered at xα with vertices at xα±1 where the number of vertices is 2d . Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A131 We consider two different constructions of AE schemes for multidimensions. For the first type, given grid values {Φα }, we construct a continuous, piecewise polynomial pα [Φ](x) ∈ Pr defined in Iα such that pα [Φ](xα±1 ) = Φα±1 . These polynomials are then put into the right-hand side of (4.1). Here Pr denotes a linear space of all polynomials of degree at most r in all xi : ⎧ ⎫ ⎨ ⎬ Pr := p | p(x) = aβ xβ , 1 ≤ i ≤ d, aβ ∈ R . ⎩ ⎭ 0≤βi ≤r Note dim(Pr ) = (r + 1)d . Sampling the AE system (4.1) at xα , which is the common vertex of Iα±1 , we obtain the semidiscrete AE scheme (4.2) 1 1 d Φα + Φα = Lα [Φ], dt Lα [Φ] = pα [Φ](xα ) − H(xk , ∇x pα [Φ](xα )). The second type will involve a dimension-by-dimension approach. For the twodimensional case, we construct a polynomial pj,k in the x-direction and qj,k in the y-direction in a similar fashion to the one-dimensional case. The AE formulation for two dimensions then becomes (4.3) 1 1 ut + u = v − H(∂x pj,k [v], ∂y qj,k [v]). An average of the p and q polynomials will be used on the v term so that the semidiscrete AE scheme becomes d 1 1 Φj,k + Φj,k = Lj,k [Φ], dt where Lj,k = pj,k [Φ](xj , yk ) + qj,k [Φ](xj , yk ) − H (∂x pj,k [Φ](xj , yk ), ∂y qj,k [Φ](xj , yk )) . 2 The strong stability-preserving Runge–Kutta method [10] can be used to achieve a time discretization with matching accuracy. 4.1. Averaging construction. We will consider the first type of construction for an AE scheme in multidimensions, which will be referred to as the averaging construction. For simplicity, we now present our AE schemes in the two-dimensional case d = 2 and use x, y instead of x1 , x2 . For mesh sizes Δx, Δy, Δt, Φnj,k will denote the numerical approximation to the viscosity solution φ(xj , yk , tn ) = φ(jΔx, kΔy, nΔt) of φt + H(φx , φy ) = 0. We shall use the notation Dx0 Φj,k = Φj+1,k − Φj−1,k , 2Δx Dy0 Φj,k = Φj,k+1 − Φj,k−1 2Δy Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. A132 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php for central differences and Ax Φj,k = Φj+1,k + Φj−1,k , 2 Ay Φj,k = Φj,k+1 + Φj,k−1 2 for averages. We begin with a continuous linear interpolation over each rectangular Ij,k centered at (xj , yk ) = (jΔx, kΔy) with vertices at (xj±1 , yk±1 ). In this case the polynomial is uniquely determined by grid values at four vertices of Ij,k satisfying pj,k [Φ](xj±1 , yk±1 ) = Φj±1,k±1 . Such an interpolant is given by p1j,k [Φ](x, y) = Ax Ay Φj,k + Dx0 Ay Φj,k (x − xj ) + Dy0 Ax Φj,k (y − yk ) + Dx0 Dy0 Φj,k (x − xj )(y − yk ). Substitution of this into the right-hand side of (4.2) and use of forward Euler timediscretization yields the first order AE scheme, (4.4) (4.5) n n Φn+1 j,k = (1 − κ)Φj,k + κLj,k [Φ ], Lj,k [Φ] = Ax Ay Φj,k − H(Dx0 Ay Φj,k , Dy0 Ax Φj,k ). The scale parameter is chosen to be max |H1 (·)| max |H2 (·)| · + ≤ 1. Δx Δy Here, Hi (p, q) is the partial derivative of H with respect to the ith argument (dependence of H on x causes no difficulty). The scheme becomes a local AE scheme with = nj,k when the maximum is taken over Ij,k for all φ = p1j,k [Φn ](x, y). Indeed, under this CFL type restriction, Lj,k [Φ] is nondecreasing in terms of its arguments. Therefore, for H(0, 0) = 0, we have a local bound for Lj,k [Φ]: {Φi,l } ≤ Lj,k [Φ] ≤ min |i−j|=1,|l−k|=1 max |i−j|=1,|l−k|=1 {Φi,l }. This, when combined with κ ≤ 1 leads to the local maximum principle min {Φi,l } ≤ Φn+1 j,k ≤ |i−j|=1,|l−k|=1 max |i−j|=1,|l−k|=1 {Φi,l }, n ∈ N. 4.2. Stability analysis of second order AE schemes. We start again assuming that Φnj,k has already been computed. We extend the linear reconstruction p1j,k [Φ] to a continuous, piecewise quadratic polynomial in Ij,k . Maintaining the interpolation at four vertices of Ij,k such a polynomial is given by p2j,k [Φ](x, y) = p1j,k [Φ](x, y) + sj,k sj,k (x − xj−1 )(x − xj+1 ) + (y − yk−1 )(y − yk+1 ), 2 2 where sj,k and sj,k are approximations to the corresponding exact derivatives φxx (xj , yk , tn ) and φyy (xj , yk , tn ), respectively. The polynomial is not unique, leaving room to impose a nonlinear limiter on the numerical derivatives to ensure the nonoscillatory Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A133 property. In our two-dimensional numerical experiments, we use the θ-refined minmod limiter, defined as follows: sj,k = MM θAy (Dx0 )2 Φj+1,k , Ay (Dx0 )2 Φj,k , θAy (Dx0 )2 Φj−1,k , (4.6) sj,k = MM θAx (Dy0 )2 Φj,k+1 , Ax (Dy0 )2 Φj,k , θAx (Dy0 )2 Φj,k−1 . (4.7) Here, θ ∈ [1, 2] is a parameter that controls numerical dissipation where θ = 1 is the most dissipative and θ = 2 is the least dissipative (see, e.g., [18]). We now substitute p2j,k [Φ](x, y) into Lj,k [Φ] to obtain the second order semidiscrete AE scheme: d 1 1 Φj,k + Φj,k = Lj,k [Φ], dt (4.8) sj,k sj,k (Δx)2 − (Δy)2 2 2 − H(Dx0 Ay Φj,k , Dy0 Ax Φj,k ). Lj,k [Φ] = Ax Ay Φj,k − (4.9) An application of the second order Runge–Kutta solver gives the fully discrete second order AE scheme: Φ∗j,k = (1 − κ)Φnj,k + κLj,k [Φn ], 1−κ 1 n κ Φ = + Φn+1 Φ∗j,k + Lj,k [Φ∗ ]. j,k 2 j,k 2 2 (4.10) (4.11) As in the one-dimensional case, for the second order scheme to still satisfy the maximum principle, we fix θ = 1 and modify the limiter as sj,k = Dx0 MM{Ay Dx0 Φj+1,k , Ay Dx0 Φj,k , Ay Dx0 Φj−1,k } , (4.12) (4.13) sj,k = Dy0 MM{Ax Dy0 Φj,k+1 , Ax Dy0 Φj,k , Ax Dy0 Φj,k−1 } . As illustrated in Figure 1 for the one-dimensional case, this modified limiter could be inferior to (4.6), (4.7), yet it ensures the maximum-satisfying property of the second order scheme. Theorem 4.1. Let Φn be computed from the second order AE scheme (4.10), (4.11), and (4.9) for HJ equations with H(0, 0) = 0 and slopes sj,k , sj,k defined in (4.12)–(4.13). If max |H1 (∇φ)| max |H2 (∇φ)| 1 + and Δt < (4.14) · ≤ Δx Δy 2 hold, then |Φn+1 |∞ ≤ |Φn |∞ , n ∈ N. Proof. It suffices to show |L[Φn ]|∞ ≤ |Φn |∞ , so that when κ < 1, we have that |Φ n+1 |∞ 1 ≤ |Φn |∞ + 2 1 κ − 2 2 |Φ∗ |∞ + κ |L[Φ∗ ]|∞ ≤ |Φn |∞ . 2 Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A134 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN We now prove (4.2) as follows. Set ⎧ sj,k ⎨ −(Δx)2 0 βj,k := Dx Ay Φj,k ⎩ 0 if Dx0 Ay Φj,k = 0, if Dx0 Ay Φj,k = 0 if Dy0 Ax Φj,k = 0, if Dy0 Ax Φj,k = 0. and βj,k := ⎧ ⎨ ⎩ −(Δy)2 sj,k Dy0 Ax Φj,k 0 Notice that H(0, 0) = 0, and by taking the Taylor expansion of the Hamiltonian we have βj,k βj,k 0 − H1 (·) Dx Ay Φj,k + − H2 (·) Dy0 Ax Φj,k , Lj,k [Φ] = Ax Ay Φj,k + 2 2 where (·) denotes some unspecified intermediate values. Regrouping terms we obtain a2 a2 1 1 a1 a1 + − Lj,k [Φ] = 1+ Φj+1,k+1 + 1+ Φj+1,k−1 4 Δx Δy 4 Δx Δy (4.15) a2 a2 1 1 a1 a1 + − + 1− Φj−1,k+1 + 1− Φj−1,k−1 , 4 Δx Δy 4 Δx Δy where a1 = βj,k − H1 (·), 2 a2 = βj,k − H2 (·). 2 Due to the minmod limiters defined in (4.12), (4.13), we claim that (4.16) |sj,k | ≤ |Ay Dx0 Φj,k | , 2Δx |sj,k | ≤ |Ax Dy0 Φj,k | . 2Δy Δx , 2 |βj,k |≤ Δy , 2 Thereby, |βj,k |≤ which when combined with the condition (4.14) yields 1 1 1 |a1 | |a2 | + ≤ + + = 1. Δx Δy 4 4 2 Thus all the coefficients on the right of (4.15) are nonnegative, and Lj,k [Φ] is a convex combination of four values Φj±1,k±1 . This implies |L[Φn ]|∞ ≤ |Φn |∞ . Finally we show claim (4.16). For the first inequality, we fix k and set bj := Ay Dx0 Φj,k and Bj = M M {bj+1 , bj , bj−1 } so that sj,k = 1 (Bj+1 − Bj−1 ). 2Δx Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A135 Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php By the definition of M M , we have 1 min{|Bj−1 |, |Bj+1 |} 2Δx 1 min2l=−2 |bj+l | ≤ 2Δx 1 |bj |. ≤ 2Δx |sj,k | ≤ The second inequality in (4.16) can be shown in same fashion. Using this averaging method, construction of schemes higher than second order will become cumbersome. We therefore adopt a dimension-by-dimension approach that can be easily derived for higher order schemes. 4.3. Dimension-by-dimension approach. We now consider the second construction method of the two-dimensional AE scheme which will be referred to as the dimension-by-dimension approach. We consider interpolated polynomials, pj,k and qj,k in the x- and y-directions, satisfying pj,k [Φ](xj±1 , yk ) = Φj±1,k , qj,k [Φ](xj , yk±1 ) = Φj,y±1 so that (4.17) Lj,k = pj,k [Φ](xj , yk ) + qj,k [Φ](xj , yk ) 2 − H (∂x pj,k [Φ](xj , yk ), ∂y qj,k [Φ](xj , yk )) . 4.3.1. First order scheme. For the first order scheme, such an interpolant is given by p1j,k [Φ](x, y) = Φj−1,k + sxj,k (x − xj−1 ), 1 [Φ](x, y) = Φj,k−1 + syj,k (y − yk−1 ), qj,k where sxj,k = Φj+1,k − Φj−1,k , 2Δx syj,k = Φj,k+1 − Φj,k−1 . 2Δy Evaluating at the polynomials and their partial derivatives at (xj , yk ) yields Φj+1,k + Φj−1,k , 2 Φj,k+1 + Φj,k−1 1 qj,k , [Φ](xj , yk ) = 2 p1j,k [Φ](xj , yk ) = ∂x p1j,k [Φ](xj , yk ) = sxj,k , 1 ∂y qj,k [Φ](xj , yk ) = syj,k . Substituting this into (4.17) yields (4.18) Lj,k [Φ] = Ax Ay Φj,k − H(sxj,k , syj,k ) so that n n Φn+1 j,k = (1 − κ)Φj,k + κLj,k [Φ ]. Note that the only difference in first order schemes for (4.5) and (4.18) is in the computation of φx and φy for H(φx , φy ). Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A136 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN 4.3.2. Second order scheme. For the second order scheme, the continuous, piecewise interpolating polynomial is given by (sxj,k ) (x − xj−1 )(x − xj+1 ), 2 (syj,k ) 2 (y − yk−1 )(y − yk+1 ), [Φ](x, y) = Φj,k−1 + syj,k (y − yj−1 ) + qj,k 2 p2j,k [Φ](x, y) = Φj−1,k + sxj,k (x − xj−1 ) + where the approximations to the second derivative are approximated using the ENO interpolation technique, x sj+2,k − sxj,k sxj,k − sxj−2,k (sxj,k ) = M , , 2Δx 2Δx y sj,k+2 − syj,k syj,k − syj,k−2 y , . (sj,k ) = M 2Δy 2Δy We then obtain (sxj,k ) Φj+1,k + Φj−1,k − (Δx)2 , 2 2 (syj,k ) Φj,k+1 + Φj,k−1 2 − (Δy)2 , [Φ](xj , yk ) = qj,k 2 2 p2j,k [Φ](xj , yk ) = ∂x p2j,k [Φ](xj , yk ) = sxj,k , 2 ∂y qj,k [Φ](xj , yk ) = syj,k , so that Lj,k [Φ] = Ax Ay Φj,k − (syj,k ) (sxj,k ) (Δx)2 − (Δy)2 − H(sxj,k , syj,k ). 2 2 Combined with a second order Runge–Kutta method this gives Φ∗j,k = (1 − κ)Φnj,k + κLj,k [Φn ], 1 n 1−κ ∗ κ Φn+1 Φj,k + Lj,k [Φ∗ ]. j,k = Φj,k + 2 2 2 Again, the only difference in second order schemes for the two types of twodimensional AE schemes is in the computation of φx and φy for H(φx , φy ). 4.3.3. Third order scheme. The third order scheme formulation is based on the cubic polynomials (sxj,k ) (x − xj−1 )(x − xj+1 )(x − x∗ ), 6 (syj,k ) 3 2 [Φ](x, y) = qj,k [Φ](x, y) + qj,k (y − yk−1 )(y − yk+1 )(y − y ∗ ), 6 p3j,k [Φ](x, y) = p2j,k [Φ](x, y) + where (sxj,k ) = M (syj,k ) =M (sxj+2,k ) − (sxj,k ) (sxj,k ) − (sxj−2,k ) , 2Δx 2Δx (syj,k+2 ) − (syj,k ) (syj,k ) − (syj,k−2 ) , 2Δy 2Δy , . Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A137 Here, x∗ is chosen as the grid point value used in the ENO procedure for (sxj,k ) so that x∗ = xj−3 or x∗ = xj+3 . The value y ∗ is chosen in a similar way. This gives (sxj,k ) (sxj,k ) Φj+1,k + Φj−1,k − (Δx)2 − (Δx)2 (x − x∗ ), 2 2 6 (sxj,k ) (Δx)2 , ∂x p3j,k = sxj,k − 6 (syj,k ) (syj,k ) Φj,k+1 + Φj,k−1 3 2 − (Δy) − (Δy)2 (y − y ∗ ), qj,k [Φ](xj , yk ) = 2 2 6 (syj,k ) 3 ∂y qj,k (Δy)2 . = syj,k − 6 p3j,k [Φ](xj , yk ) = When combined with the third order Runge–Kutta method, this gives (1) Φj,k = (1 − κ)Φnj,k + κLj,k [Φn ], 3 1 1 (2) (1) Φj,k = Φnj,k + (1 − κ)Φj,k + κLj,k [Φ(1) ], 4 4 4 1 n 2 2 (2) (2) Φn+1 ], j,k = Φj,k + (1 − κ)Φj,k + κLj,k [Φ 3 3 3 where (sj,k ) (sxj,k ) (Δx)2 − (Δy)2 2 2 (syj,k ) (sxj,k ) 2 ∗ (Δx) (x − x ) − (Δy)2 (y − y ∗ ) − 6 6 y x ) (s ) (s j,k j,k y (Δx)2 , sj,k − (Δy)2 . − H sxj,k − 6 6 y Lj,k [Φ] = Ax Ay Φj,k − Since this scheme can be easily derived for higher orders using an ENO procedure for derivative approximations, it will be used for all convergence studies in the numerical results. 5. Numerical tests. In this section, we use some model problems to numerically test the first, second, and third order global and local AE schemes. If φ is the exact solution and Φ is the computed solution, then the numerical L1 and L∞ errors in the one-dimensional case are calculated as L1 error = |φk − Φk |Δx, L∞ error = max |φk − Φk |. k k We call Q in (2.10) and (2.11) the CFL type number for our numerical tests. In calculating the numerical derivatives in the approximation, ENO constructions are used in all one-dimensional tests. The θ-refined minmod limiters (4.6), (4.7) from the averaging construction scheme are used in two-dimensional tests of the second order scheme while all convergence studies use the dimension-by-dimension approach. A performance comparison of different limiters is illustrated in Figure 1. In what follows we use N to denote the number of intervals the domain is divided into, i.e., Δx = (b − a)/N for domain [a, b]. The same notation will be used in the twodimensional case as long as the same partition number is used in both x- and ydirections. Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A138 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN Table 1 The L1 and L∞ errors for convex Hamiltonian, Example 5.1, using N equally spaced cells for global and local AE first order schemes at T = 0.5 when the solution is smooth. π2 N 10 20 40 80 160 320 640 1280 Scheme AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 L1 error 2.427554E-01 1.658496E-01 6.191588E-02 1.238305E-01 6.336444E-02 3.617763E-02 6.009927E-02 2.439781E-02 1.737636E-02 2.964582E-02 1.042672E-02 8.684065E-03 1.467102E-02 4.711692E-03 4.278979E-03 7.293956E-03 2.228255E-03 2.120360E-03 3.634536E-03 1.080074E-03 1.053280E-03 1.814853E-03 5.323055E-04 5.256089E-04 L1 order 1.0410 1.4880 0.8310 1.0805 1.4265 1.0961 1.0379 1.2486 1.0187 1.0240 1.1563 1.0303 1.0127 1.0852 1.0175 1.0072 1.0471 1.0117 1.0030 1.0220 1.0040 L∞ error 1.866756E-01 1.380253E-01 6.012093E-02 1.180291E-01 6.304142E-02 3.248349E-02 6.612020E-02 2.764345E-02 1.794381E-02 3.556733E-02 1.289366E-02 1.033219E-02 1.848597E-02 6.139405E-03 5.490336E-03 9.463572E-03 2.992475E-03 2.824118E-03 4.788741E-03 1.473178E-03 1.430170E-03 2.409586E-03 7.316975E-04 7.208656E-04 L∞ order 0.7090 1.2119 0.9521 0.8661 1.2322 0.8871 0.9107 1.1201 0.8107 0.9526 1.0801 0.9204 0.9703 1.0414 0.9634 0.9850 1.0247 0.9838 0.9920 1.0108 0.9895 Example 5.1. We first test the numerical accuracy of the designed schemes by using the Hamilton–Jacobi equation with convex Hamiltonian and with smooth initial data. The equation is Φt + (Φx + 1)2 = 0, 2 −1 ≤ x ≤ 1, with initial data Φ(x, 0) = − cos πx. For numerical accuracy results, the reference solution is computed using a fifth order WENO [14, 27], fourth order TVD Runge–Kutta [10, 9], and N = 10240 with periodic boundary conditions. In Tables 1–3, the numerical accuracy results for the first, second, and third order global and local schemes are presented when the solution is smooth (time T = 0.5 π 2 ). All the proposed methods give the desired order of accuracy. The solution becomes discontinuous at time π12 , and in Figures 2–4 we plot the solutions at time T = 1.5 π 2 . We can see that local schemes give better numerical resolution than the global schemes since they have smaller numerical viscosity. For the numerical experiments the CFL number is taken to be 0.9 and Δt = 0.9. Example 5.2. The following example is with a nonconvex Hamiltonian: 1 Φt + (Φ2x − 1)(Φ2x − 4) = 0, −1 ≤ x ≤ 1, 4 Φ(x, 0) = −2|x|. Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A139 Table 2 The L1 error for convex Hamiltonian, Example 5.1, using N equally spaced cells for global and local AE second order schemes at T = 0.5 when the solution is smooth. π2 N 10 20 40 80 160 320 640 1280 Scheme AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 L1 error 1.808044E-01 1.605897E-01 7.158793E-02 5.035859E-02 3.793765E-02 2.226361E-02 1.227800E-02 8.356335E-03 6.406106E-03 3.046794E-03 1.931040E-03 1.698534E-03 7.525114E-04 4.586449E-04 4.309275E-04 1.870988E-04 1.119356E-04 1.085638E-04 4.662925E-05 2.763822E-05 2.722453E-05 1.164294E-05 6.869442E-06 6.818169E-06 L1 order 1.9768 2.2314 1.8063 2.1095 2.2613 1.8619 2.0469 2.1516 1.9497 2.0357 2.0926 1.9966 2.0170 2.0439 1.9979 2.0090 2.0225 2.0001 2.0040 2.0107 1.9997 L∞ error 1.230779E-01 1.205706E-01 7.280369E-02 4.249643E-02 3.704884E-02 2.548232E-02 1.152047E-02 1.039131E-02 8.868757E-03 2.759160E-03 2.648734E-03 2.546340E-03 7.102240E-04 6.910419E-04 6.860096E-04 1.829021E-04 1.815522E-04 1.810838E-04 4.765022E-05 4.714968E-05 4.711239E-05 1.224287E-05 1.212996E-05 1.212727E-05 L∞ order 1.6445 1.8249 1.6235 1.9510 1.9001 1.5775 2.0991 2.0075 1.8328 1.9755 1.9559 1.9092 1.9660 1.9371 1.9302 1.9449 1.9494 1.9469 1.9628 1.9609 1.9601 Table 3 The L1 error for convex Hamiltonian, Example 5.1, using N equally spaced cells for global and 0.5 local AE third order schemes at T = π2 when the solution is smooth. N 10 20 40 80 160 320 640 1280 Scheme AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 AE AE1 AE2 L1 error 9.217579E-02 8.879066E-02 3.882247E-02 1.452062E-02 1.200976E-02 5.699280E-03 1.997324E-03 1.374387E-03 7.962369E-04 2.501019E-04 1.454294E-04 1.064920E-04 3.087791E-05 1.586493E-05 1.342152E-05 3.820356E-06 1.827268E-06 1.675592E-06 4.747847E-07 2.183270E-07 2.089154E-07 5.916589E-08 2.665971E-08 2.607256E-08 L1 order 2.8581 3.0938 2.9672 2.9650 3.2400 2.9418 3.0515 3.2988 2.9548 3.0451 3.2252 3.0151 3.0284 3.1321 3.0153 3.0151 3.0720 3.0105 3.0078 3.0372 3.0057 L∞ error 9.436562E-02 9.366517E-02 3.899054E-02 2.009461E-02 1.889613E-02 7.722367E-03 3.885110E-03 2.847301E-03 1.256969E-03 5.805090E-04 3.220735E-04 1.787705E-04 7.616378E-05 3.398078E-05 2.507739E-05 9.628130E-06 3.763566E-06 3.215076E-06 1.206421E-06 4.391123E-07 4.054263E-07 1.509158E-07 5.295197E-08 5.086366E-08 L∞ order 2.3920 2.4756 2.5041 2.4562 2.8288 2.7134 2.7920 3.2008 2.8645 2.9566 3.2738 2.8592 2.9972 3.1889 2.9768 3.0033 3.1064 2.9941 3.0023 3.0553 2.9981 Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A140 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0 0 −0.2 −0.2 −0.4 −0.4 −0.6 −0.6 −0.8 −0.8 −1 −1 −1.2 −1.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0.2 0.4 (a) AE scheme. 0.6 0.8 1 1.2 1.4 1.6 1.8 2 (b) AE1 scheme. 0.8 0.8 0.6 Reference AE AE1 AE2 0.6 0.4 0.4 0.2 0.2 0 0 −0.2 −0.2 −0.4 −0.4 −0.6 −0.6 −0.8 −0.8 −1 −1 −1.2 −1.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 (c) AE2 scheme. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 (d) Comparison with all schemes. Fig. 2. Comparison of plots for HJ equation with convex Hamiltonian, Example 5.1, at discontinuity on [−1, 1], T = 1.5/π 2 , N = 40, Δt = 0.8, first order scheme. This test problem is used to show resolution of discontinuities when the initial data has discontinuous derivatives. As in the previous problem, the reference solution is computed using a fifth order WENO [14, 27], fourth order TVD Runge–Kutta [10, 9], and N = 10240. In testing our AE methods, the CFL number used for all order schemes was 0.9. Linear extension boundary conditions are used for the numerical tests. In Figures 5–7, we can clearly see that the local AE2 scheme gives the best numerical accuracy, followed by local AE1 and the global AE for first, second, and third order methods. Example 5.3. The one-dimensional Eikonal equation is Φt + |Φx | = 0, 0 ≤ x ≤ 2π, with initial data Φ(x, 0) = sin x. The exact solution is given as in [5]: Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. A141 Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0 0 −0.2 −0.2 −0.4 −0.4 −0.6 −0.6 −0.8 −0.8 −1 −1 −1.2 −1.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0.2 0.4 (a) AE scheme. 0.6 0.8 1 1.2 1.4 1.6 1.8 2 (b) AE1 scheme. 0.8 0.8 0.6 Reference AE AE1 AE2 0.6 0.4 0.4 0.2 0.2 0 0 −0.2 −0.2 −0.4 −0.4 −0.6 −0.6 −0.8 −0.8 −1 −1 −1.2 −1.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0.2 (c) AE2 scheme. 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 (d) Comparison with all schemes. Fig. 3. Comparison of plots for HJ equation with convex Hamiltonian, Example 5.1, at discontinuity on [−1, 1], T = 1.5/π 2 , N = 40, Δt = 0.8, second order scheme. • If 0 ≤ t ≤ π/2, ⎧ sin(x − t) ⎪ ⎪ ⎪ ⎨ sin(x + t) Φ(x, t) = −1 ⎪ ⎪ ⎪ ⎩ sin(x − t) • If π/2 ≤ t ≤ π, ⎧ ⎪ ⎪ ⎪ ⎨ if if if if −1 sin(x − t) Φ(x, t) = sin(x + t) ⎪ ⎪ ⎪ ⎩ −1 0 ≤ x ≤ π/2, π/2 ≤ x ≤ 3π/2 − t, 3π/2 − t ≤ x ≤ 3π/2 + t, 3π/2 + t ≤ x ≤ 2π. if if if if 0 ≤ x ≤ t − π/2. t − π/2 ≤ x ≤ π/2. π/2 ≤ x ≤ 3π/2 − t. 3π/2 − t ≤ x ≤ 2π. • If t ≥ π, Φ(x, t) = −1. Note that local and global schemes are all the same for this example since |Hp | = 1. The numerical solution is compared for first, second, and third order schemes at time Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A142 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0 0 −0.2 −0.2 −0.4 −0.4 −0.6 −0.6 −0.8 −0.8 −1 −1 −1.2 −1.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0.2 0.4 (a) AE scheme. 0.6 0.8 1 1.2 1.4 1.6 1.8 2 (b) AE1 scheme. 0.8 0.8 0.6 Reference AE AE1 AE2 0.6 0.4 0.4 0.2 0.2 0 0 −0.2 −0.2 −0.4 −0.4 −0.6 −0.6 −0.8 −0.8 −1 −1 −1.2 −1.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 (c) AE2 scheme. 1.8 2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 (d) Comparison with all schemes. Fig. 4. Comparison of plots for HJ equation with convex Hamiltonian, Example 5.1, at discontinuity on [−1, 1], T = 1.5/π 2 , N = 40, Δt = 0.8, third order scheme. T = 1 in Figure 8. For the viscosity solution, there is a shock wave in φx at x = π/2 and a rarefaction wave at x = 3π/2. The CFL number used on the numerical tests is 0.7. Example 5.4. The two-dimensional linear HJ equation with variable coefficients is φt − yφx + xφy = 0 (5.1) with initial condition ⎧ ⎨ φ0 (x, y) = 0 if 0.3 ≤ r, 0.3 − r if 0.1 ≤ r ≤ 0.3, ⎩ 0.2 if r ≤ 0.1, where r = (x − 0.4)2 + (y − 0.4)2 . The computational domain is [−1, 1]2 and we impose periodic boundary conditions. The exact solution can be expressed as (5.2) φ(x, y, t) = φ0 (x cos(t) + y sin(t), −x sin(t) + y cos(t)). Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. A143 Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS −1 −1 −1.2 −1.2 −1.4 −1.4 −1.6 −1.6 −1.8 −1.8 −2 −1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 −2 −1 −0.8 −0.6 (a) AE scheme. −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 (b) AE1 scheme. Reference AE AE1 AE2 −1 −1 −1.2 −1.2 −1.4 −1.4 −1.6 −1.6 −1.8 −2 −1 −1.8 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 (c) AE2 scheme. 0.8 1 −2 −1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 (d) Comparison with all schemes. Fig. 5. Comparison of plots for HJ equation with Riemann initial data, Example 5.2, at discontinuity on [−1, 1], T = 1, N = 80, Δt = 0.8, first order scheme. The results for the second order schemes at time t = 2π are shown in Figure 9. We choose θ = 2 in the minmod computation for the approximations sj,k , sj,k and let Δt = .95. Here, we look along the line x = y and compare the global AE scheme to the local AE1 scheme for various mesh sizes. We can see that the local AE1 scheme provides better resolution to the exact solution for the same number of grid points as the global AE scheme. Example 5.5. We solve the two-dimensional Burgers equation using first and second order global schemes by the dimension-by-dimension approach: φt + (φx + φy + 1)2 =0 2 with initial data φ(x, y, 0) = − cos(x + y). The computational domain is [0, 2π]2 and we impose periodic boundary conditions. The solution is still smooth at time t = 0.1 and we test the order of accuracy at this time in Tables 4 and 5. For the first order and second order schemes, we get the expected order in all norms. A convergence test for the third order scheme will be applied to the problem with a nonconvex Hamiltonian (see Example 5.7). Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A144 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN −1 −1 −1.2 −1.2 −1.4 −1.4 −1.6 −1.6 −1.8 −1.8 −2 −1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 −2 −1 −0.8 −0.6 (a) AE scheme. −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 (b) AE1 scheme. Reference AE AE1 AE2 −1 −1 −1.2 −1.2 −1.4 −1.4 −1.6 −1.6 −1.8 −2 −1 −1.8 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 −2 −1 (c) AE2 scheme. −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 (d) Comparison with all schemes. Fig. 6. Comparison of plots for HJ equation with Riemann initial data, Example 5.2, at discontinuity on [−1, 1], T = 1, N = 80, Δt = 0.8, second order scheme. Example 5.6. φt + φ2x + φ2y + 1 = 0 with smooth initial data φ(x, y, 0) = 1 (cos(2πx) − 1) (cos(2πy) − 1) − 1 4 and computational domain [0, 1]2 and periodic boundary conditions. The results at time t = 0.6 are shown in Figure 10. The AE scheme provides high resolution in the formation of the singularity. Example 5.7. We now consider an example with a nonconvex Hamiltonian: φt − cos(φx + φy + 1) = 0 with initial data φ(x, y, 0) = − cos π(x + y) 2 on the computation domain [−2, 2]2 with periodic boundary conditions. At time t = 0.5 π 2 , the solution is still smooth and we test the order of accuracy for second Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. A145 Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS −1 −1 −1.2 −1.2 −1.4 −1.4 −1.6 −1.6 −1.8 −1.8 −2 −1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 −2 −1 −0.8 −0.6 (a) AE scheme. −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 (b) AE1 scheme. Reference AE AE1 AE2 −1 −1 −1.2 −1.2 −1.4 −1.4 −1.6 −1.6 −1.8 −1.8 −2 −1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 −2 −1 −0.8 (c) AE2 scheme. −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 (d) Comparison with all schemes. Fig. 7. Comparison of plots for HJ equation with Riemann initial data, Example 5.2, at discontinuity on [−1, 1], T = 1, N = 80, Δt = 0.8, third order scheme. 0.6 0.4 Reference Order 1 Order 2 Order 3 0.55 0.5 0.2 0.45 0 0.4 −0.2 0.35 −0.4 0.3 −0.6 0.25 −0.8 0.2 0.15 −1 0 1 2 3 4 (a) AE scheme. 5 6 7 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 (b) Comparison with all schemes. Fig. 8. Comparison of plots for Eikonal equation, Example 5.3, at discontinuity on [0, 2π], T = 1, N = 80, Δt = 0.9, first, second, and third order schemes. Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A146 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN 0.25 0.25 0.2 0.2 0.15 0.15 0.1 0.1 0.05 0.05 0 0 −0.05 −0.05 −0.1 −1 −0.5 0 0.5 1 −0.1 −1 (a) AE scheme, N=80. 0.25 0.2 0.2 0.15 0.1 0.1 0.05 0.05 0 0 −0.05 −0.05 −0.5 0 0.5 1 −0.1 −1 (c) AE scheme, N=160. 0.5 1 0.25 0.2 0.2 0.15 0.15 0.1 0.1 0.05 0.05 0 0 −0.05 −0.05 −0.5 0 0.5 (e) AE scheme, N=320. −0.5 0 0.5 1 (d) AE1 scheme, N=160. 0.25 −0.1 −1 0 0.25 0.15 −0.1 −1 −0.5 (b) AE1 scheme, N=80. 1 −0.1 −1 −0.5 0 0.5 1 (f) AE1 scheme, N=320. Fig. 9. Plots of second order global and local AE scheme along the line x = y for Example 5.4 at time t = 2π, where Δt = .95 and θ = 2. and third order schemes using the dimension-by-dimension approach. The results in Tables 6 and 7 show that we get the desired order in all norms. At time t = π12 , the solution develops a discontinuous derivative and results at time t = 1.5 π 2 are shown in Figure 11. 6. Concluding remarks. In this work, we have developed several AE schemes based on the alternating evolution approximation to HJ equations, motivated by our prior work on AE schemes for hyperbolic conservation laws [21, 26]. The AE system captures the exact solution when initially both components are chosen as the given initial data for the HJ equation. We numerically approximate the HJ equation by sampling two components of the AE system over alternating grids. High order accuracy is achieved by a combination of high order nonoscillatory polynomial reconstruction from the obtained grid values and an ODE solver in time discretization Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. A147 AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS L1 error 5.45124474 L1 order L2 error 0.918161204 L∞ error 0.225967148 Scheme AE 40 AE 2.831282163 0.945130159 0.491727041 0.900889782 0.130491793 0.792153966 80 AE 1.409606128 1.006163433 160 AE 0.666738528 1.080099099 0.118422976 1.068541847 0.033402227 1.035964816 320 AE 0.287707844 1.21251654 0.24836999 L2 order L∞ order N 20 0.985366826 0.068490748 0.929978053 0.051304179 1.206800783 0.014630959 1.190920009 Table 5 L1 , L2 , and L∞ comparison for Example 5.5 at time t = 0.1 using second order global AE scheme. N 20 Scheme L1 error AE 5.487583632 L1 order L2 error 0.913422858 0.27577215 L∞ error 0.214771031 L2 order L∞ order 40 AE 1.584797823 1.791872218 80 AE 0.39345259 1.727806122 0.070029702 1.616760554 160 AE 0.095952595 2.035796076 320 AE 0.022627344 2.084254579 0.004184165 2.075319525 0.001182064 2.074586915 2.010037092 0.071300662 1.951489386 0.019686339 1.830772081 0.01763365 2.01558435 0.004979134 1.983228179 Concentration at time 0.60000 Concentration at time 0.60000 1 0.9 −1.3 0.8 −1.35 −1.4 0.7 −1.45 0.6 −1.5 y Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php Table 4 L1 , L2 , and L∞ comparison for Example 5.5 at time t = 0.1 using first order global AE scheme. 0.5 −1.55 0.4 −1.6 0.3 −1.65 1 −1.7 0 0.8 0.2 0.2 0.6 0.4 0.4 0.6 0.8 0.1 0.2 1 0 y 0 0 0.1 0.2 0.3 x (a) AE scheme, Δx = Δy = 1 . 80 0.4 0.5 x 0.6 0.7 (b) AE scheme, Δx = Δy = 0.8 0.9 1 1 . 80 Fig. 10. Surface and contour plots at time t = 0.6 for Example 5.6. Table 6 L1 , L2 , and L∞ comparison for Example 5.7 at time t = by-dimension global AE scheme. N Scheme L1 error 20 AE 0.3807545007 L1 order L2 error 0.0961004734 0.5 π2 L2 order using second order dimension- L∞ error 0.0347144173 L∞ order 40 AE 0.0926199682 2.0394659222 0.0251604319 1.9333868472 0.0102422250 1.7610057921 80 AE 0.0234684717 1.9805993682 0.0064820603 1.9566323356 0.0027617696 1.8908642702 160 AE 0.0058630945 2.0009896787 0.0016286995 1.9927319161 0.0007481906 1.8841152186 320 AE 0.0014408791 2.0247129301 0.0004013811 2.0206757509 0.0001926201 1.9576475279 640 AE 0.0003416173 2.0764961041 0.0000952364 2.0753878851 0.0000465560 2.0487171898 Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php A148 HAILIANG LIU, MICHAEL POLLACK, AND HASEENA SARAN Table 7 L1 , L2 , and L∞ comparison for Example 5.7 at time t = dimension global AE scheme. N Scheme L1 error 20 AE 0.2885167659 L1 order L2 error 0.0822233536 0.5 π2 using third order dimension-by- L∞ error 0.0445854569 L2 order L∞ order 40 AE 0.0608972496 2.2442061801 0.0208873181 1.9769209512 0.0140420171 1.6668230099 80 AE 0.0122271144 2.3162931238 0.0044368628 2.2350153966 0.0034367453 2.0306353513 160 AE 0.0017583509 2.7977889587 0.0006572209 2.7550895638 0.0005444127 2.6582702568 320 AE 0.0002266868 2.9554505249 0.0000826895 2.9906021610 0.0000873968 2.6390477645 640 AE 0.0000273512 3.0510218754 0.0000097165 3.0891842742 0.0000111797 2.9666891406 1.5 1 0.5 0 −0.5 −1 −2 −1.5 −1 −0.5 0 0.5 1 1.5 2 −2 −1 0 1 2 y x Fig. 11. Surface plot for Example 5.7 at time t = dimension-by-dimension approach. 1.5 π2 with uniform mesh Δx = Δy = 1 10 using with matching accuracy. Local AE schemes are made possible by choosing the scale parameter to reflect the local distribution of nonlinear waves. The AE schemes have the advantage of easy formulation and implementation and efficient computation of the solution. For the first order local AE scheme and the second order local AE scheme with limiters, we have proved the desired maximum-satisfying property. Numerical tests for both one- and two-dimensional HJ equations presented in this work have demonstrated the high order accuracy and capacity of the AE schemes. Acknowledgment. The authors thank Professor Chiwang Shu for helpful discussions on the dimension-by-dimension ENO selection. REFERENCES [1] A. Haseena, High-Resolution Alternating Evolution Schemes for Hyperbolic Conservation Laws and Hamilton-Jacobi Equations, Ph.D. thesis, Department of Mathematics, Iowa State University, 2008. [2] S. Bryson, A. Kurganov, D. Levy, and G. Petrova, Semi-discrete central-upwind schemes with reduced dissipation for Hamilton-Jacobi equations, IMA J. Numer. Anal., 25 (2005), pp. 113–138. Copyright © by SIAM. Unauthorized reproduction of this article is prohibited. Downloaded 08/29/13 to 129.186.52.119. Redistribution subject to SIAM license or copyright; see http://www.siam.org/journals/ojsa.php AE SCHEMES FOR HAMILTON–JACOBI EQUATIONS A149 [3] S. Bryson and D. Levy, High-order central WENO schemes for multidimensional HamiltonJacobi equations, SIAM J. Numer. Anal., 41 (2003), pp. 1339–1369. [4] S. Bryson and D. Levy, High-order semi-discrete central-upwind schemes for multidimensional Hamilton-Jacobi equations, J. Comput. Phys., 189 (2003), pp. 63–87. [5] Y. Cheng and C.-W. Shu, A discontinuous Galerkin finite element method for directly solving the Hamilton-Jacobi equations, J. Comput. Phys., 223 (2007), pp. 398–415. [6] M.G. Crandall, L.C. Evans, and P.L. Lions, Some properties of viscosity solutions of Hamilton-Jacobi equations, Trans. Amer. Math. Soc., 282 (1984), pp. 487–502. [7] M.G. Crandall and P.-L. Lions, Viscosity solutions of Hamilton-Jacobi equations, Trans. Amer. Math. Soc., 277 (1983), pp. 1–42. [8] M.G. Crandall and P.-L. Lions, Two approximations of solutions of Hamilton-Jacobi equations, Math. Comp., 43 (1984), pp. 1–19. [9] S. Gottlieb and C.-W. Shu, Total variation diminishing Runge-Kutta schemes, Math. Comp., 67 (1998), pp. 73–85. [10] S. Gottlieb, C.-W. Shu, and E. Tadmor, Strong stability-preserving high-order time discretization methods, SIAM Rev., 43 (2001), pp. 89–112. [11] A. Harten, B. Engquist, S. Osher, and S.R. Chakravarthy, Uniformly high-order accurate essentially nonoscillatory schemes III, J. Comput. Phys., 71 (1987), pp. 231–303. [12] C. Hu and C.-W. Shu, A discontinuous Galerkin finite element method for Hamilton-Jacobi equations, SIAM J. Sci. Comput., 21 (1999), pp. 666–690. [13] G.-S. Jiang and D. Peng, Weighted ENO schemes for Hamilton-Jacobi equations, SIAM J. Sci. Comput., 21 (2000), pp. 2126–2143. [14] G.-S. Jiang and C.-W. Shu, Efficient implementation of weighted ENO schemes, J. Comput. Phys., 126 (1996), pp. 202–228. [15] A. Kurganov, S. Noelle, and G. Petrova, Semidiscrete central-upwind schemes for hyperbolic conservation laws and Hamilton-Jacobi equations, SIAM J. Sci. Comput., 23 (2001), pp. 707–740. [16] A. Kurganov and E. Tadmor, New high-resolution semi-discrete central schemes for Hamilton-Jacobi equations, J. Comput. Phys., 160 (2000), pp. 720–742. [17] D. Levy, S. Nayak, C.-W. Shu, and Y.-T. Zhang, Central WENO schemes for HamiltonJacobi equations on triangular meshes, SIAM J. Sci. Comput., 28 (2006), pp. 2229–2247. [18] K.-A. Lie and S. Noelle, On the artificial compression method for second-order nonoscillatory central difference schemes for systems of conservation laws, SIAM J. Sci. Comput., 24 (2003), pp. 1157–1174. [19] C.-T. Lin and E. Tadmor, High-resolution nonoscillatory central schemes for Hamilton-Jacobi equations, SIAM J. Sci. Comput., 21 (2000), pp. 2163–2186. [20] C.-T. Lin and E. Tadmor, L1 -stability and error estimates for approximate Hamilton-Jacobi solutions, Numer. Math., 87 (2001), pp. 701–735. [21] H. Liu, An alternating evolution approximation to systems of hyperbolic conservation laws, J. Hyperbolic Differ. Equ., 5 (2008), pp. 1–27. [22] F.Y. Li and S. Yakovlev, A central discontinuous Galerkin method for Hamilton-Jacobi equations, J. Sci. Comput., 45 (2010), pp. 404–428. [23] Y. Liu, Central schemes on overlapping cells, J. Comput. Phys., 209 (2005), pp. 82–104. [24] S. Osher and J.A. Sethian, Fronts propagating with curvature-dependent speed: Algorithms based on Hamilton-Jacobi formulations, J. Comput. Phys., 79 (1988), pp. 12–49. [25] S. Osher and C.-W. Shu, High-order essentially nonoscillatory schemes for Hamilton-Jacobi equations, SIAM J. Numer. Anal., 28 (1991), pp. 907–922. [26] H. Saran and H. Liu, Formulation and analysis of alternating evolution schemes for conservation laws, SIAM J. Sci. Comput., 33 (2011), pp. 3210–3240. [27] C.-W. Shu, High order ENO and WENO schemes for computational fluid dynamics, in HighOrder Methods for Computational Physics, Lect. Notes Comput. Sci. Eng. 9, Springer, Berlin, 1999, pp. 439–582. [28] J. Qiu and C.W. Shu, Hermite WENO schemes for Hamilton-Jacobi equations, J. Comput. Phys., 204 (2005), pp. 82–99. [29] P.E. Souganidis, Approximation schemes for viscosity solutions of Hamilton-Jacobi equations, J. Differential Equations, 59 (1985), pp. 1–43. [30] J. Yan and S. Osher, A new discontinuous Galerkin method for Hamilton-Jacobi equations, J. Comput. Phys., 230 (2011), pp. 232–244. [31] Y.-T. Zhang and C.-W. Shu, High order WENO schemes for Hamilton-Jacobi equations on triangular meshes, SIAM J. Sci. Comput., 24 (2003), pp. 1005–1030. Copyright © by SIAM. Unauthorized reproduction of this article is prohibited.