Mercurial > repos > public > sbplib
changeset 1333:0aefcb30cab4 feature/D2_boundary_opt
Add support for RK6
| author | Vidar Stiernström <vidar.stiernstrom@it.uu.se> |
|---|---|
| date | Sat, 07 May 2022 10:30:59 +0200 |
| parents | 8e9df030a0a5 |
| children | df8c71b80c33 |
| files | +time/+rkparameters/rk6.m +time/ExplicitRungeKuttaDiscreteData.m |
| diffstat | 2 files changed, 15 insertions(+), 0 deletions(-) [+] |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/+time/+rkparameters/rk6.m Sat May 07 10:30:59 2022 +0200 @@ -0,0 +1,13 @@ +function [a,b,c,s] = rk6() + % Runge-Kutta 6 from Alshina07 + s = 7; + a = sparse(s,s-1); + a(2,1) = 4/7; + a(3,1) = 115/112; a(3,2) = -5/16; + a(4,1) = 589/630; a(4,2) = 5/18; a(4,3) = -16/45; + a(5,1) = 229/1200 - 29/6000*sqrt(5); a(5,2) = 119/240 - 187/1200*sqrt(5); a(5,3) = -14/75 + 34/375*sqrt(5); a(5,4) = -3/100*sqrt(5); + a(6,1) = 71/2400 - 587/12000*sqrt(5); a(6,2) = 187/480 - 391/2400*sqrt(5); a(6,3) = -38/75 + 26/375*sqrt(5); a(6,4) = 27/80 - 3/400*sqrt(5); a(6,5) = (1+sqrt(5))/4; + a(7,1) = -49/480 + 43/160*sqrt(5); a(7,2) = -425/96 + 51/32*sqrt(5); a(7,3) = 52/15 - 4/5*sqrt(5); a(7,4) = -27/16 + 3/16*sqrt(5); a(7,5) = 5/4 - 3/4*sqrt(5); a(7,6) = 5/2 - 1/2*sqrt(5); + b = [1/12; 0; 0; 0; 5/12; 5/12; 1/12]; + c = [0; 4/7; 5/7; 6/7; (5-sqrt(5))/10; (5+sqrt(5))/10; 1]; +end \ No newline at end of file
--- a/+time/ExplicitRungeKuttaDiscreteData.m Wed May 04 08:42:13 2022 +0200 +++ b/+time/ExplicitRungeKuttaDiscreteData.m Sat May 07 10:30:59 2022 +0200 @@ -35,6 +35,8 @@ switch order case 4 [obj.a, obj.b, obj.c, obj.s] = time.rkparameters.rk4(); + case 6 + [obj.a, obj.b, obj.c, obj.s] = time.rkparameters.rk6(); otherwise error('That RK method is not available'); end