comparison +sbp/+implementations/d1_noneq_6.m @ 1286:4cb627c7fb90 feature/boundary_optimized_grids

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_6(N,L) 1 function [D1,H] = d1_noneq_6(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<12) 4 if(N<12)
10 error('Operator requires at least 12 grid points'); 5 error('Operator requires at least 12 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 = 6; 9 BP = 6;
17 m = 3;
18 order = 6;
19
20 %%%% Non-equidistant grid points %%%%%
21 x0 = 0.0000000000000e+00;
22 x1 = 4.4090263368623e-01;
23 x2 = 1.2855984345073e+00;
24 x3 = 2.2638953951239e+00;
25 x4 = 3.2638953951239e+00;
26 x5 = 4.2638953951239e+00;
27 x6 = 5.2638953951239e+00;
28
29 xb = sparse(m+1,1);
30 for i = 0:m
31 xb(i+1) = eval(['x' num2str(i)]);
32 end
33 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
34
35 %%%% Compute h %%%%%%%%%%
36 h = L/(2*xb(end) + N-1-2*m);
37 %%%%%%%%%%%%%%%%%%%%%%%%%
38
39 %%%% Define grid %%%%%%%%
40 x = h*[xb; linspace(xb(end)+1,L/h-xb(end)-1,N-2*(m+1))'; L/h-flip(xb) ];
41 %%%%%%%%%%%%%%%%%%%%%%%%%
42 10
43 %%%% Norm matrix %%%%%%%% 11 %%%% Norm matrix %%%%%%%%
44 P = sparse(BP,1); 12 P = sparse(BP,1);
45 %#ok<*NASGU> 13 %#ok<*NASGU>
46 P0 = 1.3030223027124e-01; 14 P0 = 1.3030223027124e-01;
59 H(end-BP+1:end) = flip(P); 27 H(end-BP+1:end) = flip(P);
60 H = spdiags(h*H,0,N,N); 28 H = spdiags(h*H,0,N,N);
61 %%%%%%%%%%%%%%%%%%%%%%%%% 29 %%%%%%%%%%%%%%%%%%%%%%%%%
62 30
63 %%%% Q matrix %%%%%%%%%%% 31 %%%% Q matrix %%%%%%%%%%%
64
65 % interior stencil 32 % interior stencil
66 switch order 33 order = 6;
67 case 2 34 d = [-1/60,3/20,-3/4,0,3/4,-3/20,1/60];
68 d = [-1/2,0,1/2];
69 case 4
70 d = [1/12,-2/3,0,2/3,-1/12];
71 case 6
72 d = [-1/60,3/20,-3/4,0,3/4,-3/20,1/60];
73 case 8
74 d = [1/280,-4/105,1/5,-4/5,0,4/5,-1/5,4/105,-1/280];
75 case 10
76 d = [-1/1260,5/504,-5/84,5/21,-5/6,0,5/6,-5/21,5/84,-5/504,1/1260];
77 case 12
78 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];
79 end
80 d = repmat(d,N,1); 35 d = repmat(d,N,1);
81 Q = spdiags(d,-order/2:order/2,N,N); 36 Q = spdiags(d,-order/2:order/2,N,N);
82 37
83 % Boundaries 38 % Boundaries
84 Q0_0 = -5.0000000000000e-01; 39 Q0_0 = -5.0000000000000e-01;