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comparison +sbp/+implementations/d1_noneq_8.m @ 1286:4cb627c7fb90 feature/boundary_optimized_grids

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Make D1Nonequidistant use the grid generation functions accurate/minimalBoundaryOptimizedGrid and remove grid generation from +implementations
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Wed, 01 Jul 2020 13:43:32 +0200
parents f7ac3cd6eeaa
children
comparison
equal deleted inserted replaced
1285:6b68f939d023 1286:4cb627c7fb90
1 function [D1,H,x,h] = d1_noneq_8(N,L) 1 function [D1,H] = d1_noneq_8(N,h)
2 2
3 % L: Domain length
4 % N: Number of grid points 3 % N: Number of grid points
5 if(nargin < 2)
6 L = 1;
7 end
8
9 if(N<16) 4 if(N<16)
10 error('Operator requires at least 16 grid points'); 5 error('Operator requires at least 16 grid points');
11 end 6 end
12 7
13 % BP: Number of boundary points 8 % BP: Number of boundary points
14 % m: Number of nonequidistant spacings
15 % order: Accuracy of interior stencil
16 BP = 8; 9 BP = 8;
17 m = 4;
18 order = 8;
19
20 %%%% Non-equidistant grid points %%%%%
21 x0 = 0.0000000000000e+00;
22 x1 = 3.8118550247622e-01;
23 x2 = 1.1899550868338e+00;
24 x3 = 2.2476300175641e+00;
25 x4 = 3.3192851303204e+00;
26 x5 = 4.3192851303204e+00;
27 x6 = 5.3192851303204e+00;
28 x7 = 6.3192851303204e+00;
29 x8 = 7.3192851303204e+00;
30
31 xb = sparse(m+1,1);
32 for i = 0:m
33 xb(i+1) = eval(['x' num2str(i)]);
34 end
35 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
36
37 %%%% Compute h %%%%%%%%%%
38 h = L/(2*xb(end) + N-1-2*m);
39 %%%%%%%%%%%%%%%%%%%%%%%%%
40
41 %%%% Define grid %%%%%%%%
42 x = h*[xb; linspace(xb(end)+1,L/h-xb(end)-1,N-2*(m+1))'; L/h-flip(xb) ];
43 %%%%%%%%%%%%%%%%%%%%%%%%%
44 10
45 %%%% Norm matrix %%%%%%%% 11 %%%% Norm matrix %%%%%%%%
46 P = sparse(BP,1); 12 P = sparse(BP,1);
47 %#ok<*NASGU> 13 %#ok<*NASGU>
48 P0 = 1.0758368078310e-01; 14 P0 = 1.0758368078310e-01;
63 H(end-BP+1:end) = flip(P); 29 H(end-BP+1:end) = flip(P);
64 H = spdiags(h*H,0,N,N); 30 H = spdiags(h*H,0,N,N);
65 %%%%%%%%%%%%%%%%%%%%%%%%% 31 %%%%%%%%%%%%%%%%%%%%%%%%%
66 32
67 %%%% Q matrix %%%%%%%%%%% 33 %%%% Q matrix %%%%%%%%%%%
68
69 % interior stencil 34 % interior stencil
70 switch order 35 order = 8;
71 case 2 36 d = [1/280,-4/105,1/5,-4/5,0,4/5,-1/5,4/105,-1/280];
72 d = [-1/2,0,1/2];
73 case 4
74 d = [1/12,-2/3,0,2/3,-1/12];
75 case 6
76 d = [-1/60,3/20,-3/4,0,3/4,-3/20,1/60];
77 case 8
78 d = [1/280,-4/105,1/5,-4/5,0,4/5,-1/5,4/105,-1/280];
79 case 10
80 d = [-1/1260,5/504,-5/84,5/21,-5/6,0,5/6,-5/21,5/84,-5/504,1/1260];
81 case 12
82 d = [1/5544,-1/385,1/56,-5/63,15/56,-6/7,0,6/7,-15/56,5/63,-1/56,1/385,-1/5544];
83 end
84 d = repmat(d,N,1); 37 d = repmat(d,N,1);
85 Q = spdiags(d,-order/2:order/2,N,N); 38 Q = spdiags(d,-order/2:order/2,N,N);
86 39
87 % Boundaries 40 % Boundaries
88 Q0_0 = -5.0000000000000e-01; 41 Q0_0 = -5.0000000000000e-01;