Mercurial > repos > public > sbplib
annotate +sbp/+implementations/d4_compatible_2.m @ 1337:bf2554f1825d feature/D2_boundary_opt
Add periodic D1 and D2 operators for orders 8,10,12
author | Vidar Stiernström <vidar.stiernstrom@it.uu.se> |
---|---|
date | Fri, 13 May 2022 13:28:10 +0200 |
parents | f7ac3cd6eeaa |
children |
rev | line source |
---|---|
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
1 function [H, HI, D1, D4, e_1, e_m, M4, Q, S2_1, S2_m,... |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
2 S3_1, S3_m, S_1, S_m] = d4_compatible_2(m,h) |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
3 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
4 %%% 4:de ordn. SBP Finita differens %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
5 %%% operatorer framtagna av Ken Mattsson %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
6 %%% %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
7 %%% 6 randpunkter, diagonal norm %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
8 %%% %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
9 %%% Datum: 2013-11-11 %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
10 %%% %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
11 %%% %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
12 %%% H (Normen) %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
13 %%% D1 (approx f?rsta derivatan) %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
14 %%% D2 (approx andra derivatan) %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
15 %%% D3 (approx tredje derivatan) %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
16 %%% D2 (approx fj?rde derivatan) %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
17 %%% %%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
18 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
19 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
20 % M?ste ange antal punkter (m) och stegl?ngd (h) |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
21 % Notera att dessa opetratorer ?r framtagna f?r att anv?ndas n?r |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
22 % vi har 3de och 4de derivator i v?r PDE |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
23 % I annat fall anv?nd de "traditionella" som har noggrannare |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
24 % randsplutningar f?r D1 och D2 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
25 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
26 % Vi b?rjar med normen. Notera att alla SBP operatorer delar samma norm, |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
27 % vilket ?r n?dv?ndigt f?r stabilitet |
266
bfa130b7abf6
Added error message for too few grid points to all implementation files.
Martin Almquist <martin.almquist@it.uu.se>
parents:
261
diff
changeset
|
28 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
29 BP = 4; |
266
bfa130b7abf6
Added error message for too few grid points to all implementation files.
Martin Almquist <martin.almquist@it.uu.se>
parents:
261
diff
changeset
|
30 if(m<2*BP) |
bfa130b7abf6
Added error message for too few grid points to all implementation files.
Martin Almquist <martin.almquist@it.uu.se>
parents:
261
diff
changeset
|
31 error(['Operator requires at least ' num2str(2*BP) ' grid points']); |
bfa130b7abf6
Added error message for too few grid points to all implementation files.
Martin Almquist <martin.almquist@it.uu.se>
parents:
261
diff
changeset
|
32 end |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
33 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
34 H=speye(m,m);H(1,1)=1/2;H(m,m)=1/2; |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
35 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
36 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
37 H=H*h; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
38 HI=inv(H); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
39 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
40 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
41 % First derivative SBP operator, 1st order accurate at first 6 boundary points |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
42 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
43 q1=1/2; |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
44 % Q=q1*(diag(ones(m-1,1),1)-diag(ones(m-1,1),-1)); |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
45 stencil = [-q1,0,q1]; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
46 d = (length(stencil)-1)/2; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
47 diags = -d:d; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
48 Q = stripeMatrix(stencil, diags, m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
49 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
50 %Q=(-1/12*diag(ones(m-2,1),2)+8/12*diag(ones(m-1,1),1)-8/12*diag(ones(m-1,1),-1)+1/12*diag(ones(m-2,1),-2)); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
51 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
52 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
53 e_1=sparse(m,1);e_1(1)=1; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
54 e_m=sparse(m,1);e_m(m)=1; |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
55 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
56 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
57 D1=H\(Q-1/2*(e_1*e_1')+1/2*(e_m*e_m')) ; |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
58 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
59 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
60 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
61 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
62 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
63 % Second derivative, 1st order accurate at first 6 boundary points |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
64 % m1=-1;m0=2; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
65 % % M=m1*(diag(ones(m-1,1),1)+diag(ones(m-1,1),-1))+m0*diag(ones(m,1),0);M(1,1)=1;M(m,m)=1; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
66 % stencil = [m2,m1,m0,m1,m2]; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
67 % d = (length(stencil)-1)/2; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
68 % diags = -d:d; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
69 % M = stripeMatrix(stencil, diags, m); |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
70 % M=M/h; |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
71 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
72 S_U=[-1 1]/h; |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
73 S_1=sparse(1,m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
74 S_1(1:2)=S_U; |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
75 S_m=sparse(1,m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
76 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
77 S_m(m-1:m)=fliplr(-S_U); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
78 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
79 % D2=H\(-M-e_1*S_1+e_m*S_m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
80 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
81 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
82 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
83 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
84 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
85 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
86 % Third derivative, 1st order accurate at first 6 boundary points |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
87 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
88 % q2=1/2;q1=-1; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
89 % % Q3=q2*(diag(ones(m-2,1),2)-diag(ones(m-2,1),-2))+q1*(diag(ones(m-1,1),1)-diag(ones(m-1,1),-1)); |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
90 % stencil = [-q2,-q1,0,q1,q2]; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
91 % d = (length(stencil)-1)/2; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
92 % diags = -d:d; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
93 % Q3 = stripeMatrix(stencil, diags, m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
94 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
95 %QQ3=(-1/8*diag(ones(m-3,1),3) + 1*diag(ones(m-2,1),2) - 13/8*diag(ones(m-1,1),1) +13/8*diag(ones(m-1,1),-1) -1*diag(ones(m-2,1),-2) + 1/8*diag(ones(m-3,1),-3)); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
96 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
97 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
98 % Q3_U = [0 -0.2e1 / 0.5e1 0.3e1 / 0.10e2 0.1e1 / 0.10e2; 0.2e1 / 0.5e1 0 -0.7e1 / 0.10e2 0.3e1 / 0.10e2; -0.3e1 / 0.10e2 0.7e1 / 0.10e2 0 -0.9e1 / 0.10e2; -0.1e1 / 0.10e2 -0.3e1 / 0.10e2 0.9e1 / 0.10e2 0;]; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
99 % Q3(1:4,1:4)=Q3_U; |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
100 % Q3(m-3:m,m-3:m)=rot90( -Q3_U ,2 ); |
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
101 % Q3=Q3/h^2; |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
102 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
103 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
104 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
105 S2_U=[1 -2 1;]/h^2; |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
106 S2_1=sparse(1,m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
107 S2_1(1:3)=S2_U; |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
108 S2_m=sparse(1,m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
109 S2_m(m-2:m)=fliplr(S2_U); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
110 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
111 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
112 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
113 % D3=H\(Q3 - e_1*S2_1 + e_m*S2_m +1/2*(S_1'*S_1) -1/2*(S_m'*S_m) ) ; |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
114 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
115 % Fourth derivative, 0th order accurate at first 6 boundary points (still |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
116 % yield 4th order convergence if stable: for example u_tt=-u_xxxx |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
117 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
118 m2=1;m1=-4;m0=6; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
119 M4=m2*(diag(ones(m-2,1),2)+diag(ones(m-2,1),-2))+m1*(diag(ones(m-1,1),1)+diag(ones(m-1,1),-1))+m0*diag(ones(m,1),0); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
120 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
121 %M4=(-1/6*(diag(ones(m-3,1),3)+diag(ones(m-3,1),-3) ) + 2*(diag(ones(m-2,1),2)+diag(ones(m-2,1),-2)) -13/2*(diag(ones(m-1,1),1)+diag(ones(m-1,1),-1)) + 28/3*diag(ones(m,1),0)); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
122 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
123 M4_U=[0.4e1 / 0.5e1 -0.7e1 / 0.5e1 0.2e1 / 0.5e1 0.1e1 / 0.5e1; -0.7e1 / 0.5e1 0.16e2 / 0.5e1 -0.11e2 / 0.5e1 0.2e1 / 0.5e1; 0.2e1 / 0.5e1 -0.11e2 / 0.5e1 0.21e2 / 0.5e1 -0.17e2 / 0.5e1; 0.1e1 / 0.5e1 0.2e1 / 0.5e1 -0.17e2 / 0.5e1 0.29e2 / 0.5e1;]; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
124 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
125 M4(1:4,1:4)=M4_U; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
126 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
127 M4(m-3:m,m-3:m)=rot90( M4_U ,2 ); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
128 M4=M4/h^3; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
129 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
130 S3_U=[-1 3 -3 1;]/h^3; |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
131 S3_1=sparse(1,m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
132 S3_1(1:4)=S3_U; |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
133 S3_m=sparse(1,m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
134 S3_m(m-3:m)=fliplr(-S3_U); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
135 |
267
f7ac3cd6eeaa
Sparsified all implementation files, removed all matlab warnings, fixed small bugs on minimum grid points.
Martin Almquist <martin.almquist@it.uu.se>
parents:
266
diff
changeset
|
136 D4=H\(M4-e_1*S3_1+e_m*S3_m + S_1'*S2_1-S_m'*S2_m); |
261
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
137 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
138 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
139 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
140 S_1 = S_1'; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
141 S_m = S_m'; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
142 S2_1 = S2_1'; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
143 S2_m = S2_m'; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
144 S3_1 = S3_1'; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
145 S3_m = S3_m'; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
146 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
147 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
148 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
149 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
150 % L=h*(m-1); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
151 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
152 % x1=linspace(0,L,m)'; |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
153 % x2=x1.^2/fac(2); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
154 % x3=x1.^3/fac(3); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
155 % x4=x1.^4/fac(4); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
156 % x5=x1.^5/fac(5); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
157 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
158 % x0=x1.^0/fac(1); |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
159 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
160 |
6009f2712d13
Moved and renamned all implementations.
Martin Almquist <martin.almquist@it.uu.se>
parents:
diff
changeset
|
161 end |