Mercurial > repos > public > sbplib
diff +time/+rk4/rungekutta_4RV.m @ 835:008496ca38f3 feature/burgers1d
Compute the residual in between each runge-kutta stage.
Note: It is not clear whether the correct residual is used when computing the stages. Must investigate further.
| author | Vidar Stiernström <vidar.stiernstrom@it.uu.se> |
|---|---|
| date | Thu, 13 Sep 2018 18:14:54 +0200 |
| parents | |
| children | 619561e9ec0e |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/+time/+rk4/rungekutta_4RV.m Thu Sep 13 18:14:54 2018 +0200 @@ -0,0 +1,18 @@ +% Takes one time step of size k using the rungekutta method +% starting from v_0 and where the function F(v,t) gives the +% time derivatives. +function v = rungekutta_4RV(v, t , k, F, RV) + k1 = F(v, t, RV.getViscosity()); + + RV.update(v+0.5*k*k1, v, 0.5*k); + k2 = F(v+0.5*k*k1, t+0.5*k, RV.getViscosity()); + + RV.update(v+0.5*k*k2, v, 0.5*k); + k3 = F(v+0.5*k*k2, t+0.5*k, RV.getViscosity()); + + RV.update(v+k*k3, v, k); + k4 = F(v+k*k3,t+k, RV.getViscosity()); + + RV.update(v + (1/6)*(k1+2*(k2+k3)+k4)*k, v, k); + v = v + (1/6)*(k1+2*(k2+k3)+k4)*k; +end \ No newline at end of file