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comparison +sbp/D4Variable.m @ 886:8894e9c49e40 feature/timesteppers

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Merge with default for latest changes
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Thu, 15 Nov 2018 16:36:21 -0800
parents 42c89b5eedc0
children
comparison
equal deleted inserted replaced
816:b5e5b195da1e 886:8894e9c49e40
1 classdef D4Variable < sbp.OpSet
2 properties
3 m % Number of grid points.
4 h % Step size
5 x % grid
6 H % Norm matrix
7 HI % H^-1
8 D1 % SBP operator approximating first derivative
9 D2 % SBP operator for second derivative
10 D4 % SBP operator for fourth derivative
11 Q % Skew-symmetric matrix
12 M % Norm matrix, second derivative
13 M4 % Norm matrix, fourth derivative
14 e_l, e_r % Left and right boundary operator
15 d1_l, d1_r % Left and right boundary first derivative
16 d2_l, d2_r % Left and right boundary second derivative
17 d3_l, d3_r % Left and right boundary third derivative
18 borrowing % Struct with borrowing limits for different norm matrices
19 order
20 end
21
22 methods
23 function obj = D4Variable(m, lim, order)
24 x_l = lim{1};
25 x_r = lim{2};
26 L = x_r-x_l;
27 obj.h = L/(m-1);
28 obj.x = linspace(x_l, x_r,m)';
29
30 if order == 2
31 [H, HI, D1, D2, D4, e_l, e_r, M4, d2_l, d2_r, d3_l, d3_r, d1_l, d1_r] = ...
32 sbp.implementations.d4_variable_2(m, obj.h);
33 obj.borrowing.M.d1 = 0.4000;
34 obj.borrowing.N.S2 = 1.2500;
35 obj.borrowing.N.S3 = 0.4000;
36 elseif order == 4
37 [H, HI, D1, D2, D4, e_l, e_r, M4, d2_l, d2_r, d3_l, d3_r, d1_l, d1_r] = ...
38 sbp.implementations.d4_variable_4(m, obj.h);
39 obj.borrowing.M.d1 = 0.2508;
40 obj.borrowing.N.S2 = 0.5055;
41 obj.borrowing.N.S3 = 0.9290;
42 elseif order == 6
43 [H, HI, D1, D2, D4, e_l, e_r, M4, d2_l, d2_r, d3_l, d3_r, d1_l, d1_r] = ...
44 sbp.implementations.d4_variable_6(m, obj.h);
45 obj.borrowing.M.d1 = 0.1878;
46 obj.borrowing.N.S2 = 0.3259;
47 obj.borrowing.N.S3 = 0.1580;
48 else
49 error('Invalid operator order.');
50 end
51
52 obj.m = m;
53 obj.order = order;
54
55 obj.H = H;
56 obj.HI = HI;
57 obj.D1 = D1;
58 obj.D2 = D2;
59 obj.D4 = D4;
60 obj.M4 = M4;
61 obj.e_l = e_l;
62 obj.e_r = e_r;
63 obj.d1_l = d1_l;
64 obj.d1_r = d1_r;
65 obj.d2_l = d2_l;
66 obj.d2_r = d2_r;
67 obj.d3_l = d3_l;
68 obj.d3_r = d3_r;
69 end
70
71 function str = string(obj)
72 str = [class(obj) '_' num2str(obj.order)];
73 end
74 end
75 end