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comparison +sbp/+implementations/d1_upwind_3.m @ 261:6009f2712d13 operator_remake

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Moved and renamned all implementations.
author Martin Almquist <martin.almquist@it.uu.se>
date Thu, 08 Sep 2016 15:35:45 +0200
parents
children bfa130b7abf6
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260:b4116ce49ac4 261:6009f2712d13
1 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_3(m,h)
2 Hv = ones(m,1);
3 Hv(1:3) = [3/8; 7/6; 23/24];
4 Hv(m-2:m) = rot90(Hv(1:3),2);
5 Hv = Hv*h;
6 H = spdiag(Hv,0);
7 HI = spdiag(1./Hv,0);
8
9 q_diags = [-1, 0, 1, 2];
10 q_stencil = [-1/3 -1/2 1 -1/6];
11 Qp = stripeMatrix(q_stencil, q_diags,m);
12
13 Q_U = [
14 -1/24 17/24 -1/6;
15 -13/24 -1/4 23/24;
16 1/12 -11/24 -11/24;
17 ];
18 Qp(1:3,1:3)=Q_U;
19 Qp(m-2:m,m-2:m)=rot90(Q_U,2)'; %%% This is different from standard SBP
20
21 Qm=-Qp';
22
23 e_1=sparse(m,1);
24 e_1(1)=1;
25 e_m=sparse(m,1);
26 e_m(m)=1;
27
28 Dp=HI*(Qp-1/2*e_1*e_1'+1/2*e_m*e_m') ;
29
30 Dm=HI*(Qm-1/2*e_1*e_1'+1/2*e_m*e_m') ;
31 end
32