Mercurial > repos > public > sbplib
annotate +time/Rk4SecondOrderNonlin.m @ 774:66eb4a2bbb72 feature/grids
Remove default scaling of the system.
The scaling doens't seem to help actual solutions. One example that fails in the flexural code.
With large timesteps the solutions seems to blow up. One particular example is profilePresentation
on the tdb_presentation_figures branch with k = 0.0005
| author | Jonatan Werpers <jonatan@werpers.com> |
|---|---|
| date | Wed, 18 Jul 2018 15:42:52 -0700 |
| parents | cd2e28c5ecd2 |
| children | b5e5b195da1e c6fcee3fcf1b |
| rev | line source |
|---|---|
| 0 | 1 classdef Rk4SecondOrderNonlin < time.Timestepper |
| 2 properties | |
| 3 F | |
| 4 k | |
| 5 t | |
| 6 w | |
| 7 m | |
| 8 | |
| 9 D | |
| 10 E | |
| 11 S | |
| 12 | |
| 13 n | |
| 14 end | |
| 15 | |
| 16 | |
| 17 methods | |
| 18 function obj = Rk4SecondOrderNonlin(D, E, S, k, t0, v0, v0t) | |
|
1
5ae4f23d9130
Added CdiffNonlin timestepper. Probably fixed a bug with Cdiff. Added default arguments to Rk4SecondOrderNonlin.
Jonatan Werpers <jonatan@werpers.com>
parents:
0
diff
changeset
|
19 default_arg('S',0); |
|
5ae4f23d9130
Added CdiffNonlin timestepper. Probably fixed a bug with Cdiff. Added default arguments to Rk4SecondOrderNonlin.
Jonatan Werpers <jonatan@werpers.com>
parents:
0
diff
changeset
|
20 default_arg('E',0); |
| 0 | 21 |
|
30
cd2e28c5ecd2
Corrected parameter treatment in nonlin timesteppers.
Jonatan Werpers <jonatan@werpers.com>
parents:
28
diff
changeset
|
22 if isnumeric(S) |
|
cd2e28c5ecd2
Corrected parameter treatment in nonlin timesteppers.
Jonatan Werpers <jonatan@werpers.com>
parents:
28
diff
changeset
|
23 S = @(v,t)S; |
| 0 | 24 end |
| 25 | |
|
30
cd2e28c5ecd2
Corrected parameter treatment in nonlin timesteppers.
Jonatan Werpers <jonatan@werpers.com>
parents:
28
diff
changeset
|
26 if isnumeric(E) |
|
cd2e28c5ecd2
Corrected parameter treatment in nonlin timesteppers.
Jonatan Werpers <jonatan@werpers.com>
parents:
28
diff
changeset
|
27 E = @(v)E; |
| 0 | 28 end |
| 29 | |
| 30 obj.k = k; | |
| 31 obj.t = t0; | |
| 32 obj.w = [v0; v0t]; | |
| 33 | |
| 34 m = length(v0); | |
| 35 function wt = F(w,t) | |
| 36 v = w(1:m); | |
| 37 vt = w(m+1:end); | |
| 38 | |
| 39 % Def: w = [v; vt] | |
| 40 wt(1:m,1) = vt; | |
| 41 wt(m+1:2*m,1) = D(v)*v + E(v)*vt + S(v,t); | |
| 42 | |
| 43 end | |
| 44 | |
| 45 obj.F = @F; | |
| 46 obj.D = D; | |
| 47 obj.E = E; | |
| 48 obj.S = S; | |
| 49 obj.m = m; | |
|
13
b18d3d201a71
Fixed initialization of step counter in timesteppers.
Jonatan Werpers <jonatan@werpers.com>
parents:
1
diff
changeset
|
50 obj.n = 0; |
| 0 | 51 end |
| 52 | |
| 53 function [v,t] = getV(obj) | |
| 54 v = obj.w(1:end/2); | |
| 55 t = obj.t; | |
| 56 end | |
| 57 | |
| 58 function [vt,t] = getVt(obj) | |
| 59 vt = obj.w(end/2+1:end); | |
| 60 t = obj.t; | |
| 61 end | |
| 62 | |
| 63 function obj = step(obj) | |
| 64 obj.w = time.rk4.rungekutta_4(obj.w, obj.t, obj.k, obj.F); | |
| 65 obj.t = obj.t + obj.k; | |
| 66 obj.n = obj.n + 1; | |
| 67 end | |
| 68 end | |
| 69 | |
| 70 | |
| 71 methods (Static) | |
| 72 function k = getTimeStep(lambda) | |
| 73 k = rk4.get_rk4_time_step(lambda); | |
| 74 end | |
| 75 end | |
| 76 | |
| 77 end |