Mercurial > repos > public > sbplib
diff +time/RungekuttaRV.m @ 846:c6fcee3fcf1b feature/burgers1d
Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
author | Vidar Stiernström <vidar.stiernstrom@it.uu.se> |
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date | Thu, 20 Sep 2018 17:51:19 +0200 |
parents | |
children | ab2e5a24ddde |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/+time/RungekuttaRV.m Thu Sep 20 17:51:19 2018 +0200 @@ -0,0 +1,50 @@ +classdef RungekuttaRV < time.Timestepper + properties + F % RHS of the ODE + k % Time step + t % Time point + v % Solution vector + n % Time level + RV % Residual Viscosity + coeffs % The coefficents used for the RK time integration + end + + methods + function obj = RungekuttaRV(F, k, t0, v0, RV, order) + obj.F = F; + obj.k = k; + obj.t = t0; + obj.v = v0; + obj.n = 0; + obj.RV = RV; + % Extract the coefficients for the specified order + % used for the RK updates from the Butcher tableua. + [s,a,b,c] = time.rk.butcherTableau(order); + obj.coeffs = struct('s',s,'a',a,'b',b,'c',c); + end + + function [v, t] = getV(obj) + v = obj.v; + t = obj.t; + end + + function state = getState(obj) + [residual, u_t, f_x] = obj.RV.getResidual(); + state = struct('v', obj.v, 'residual', residual, 'u_t', u_t, 'f_x', f_x, 'viscosity', obj.RV.getViscosity(), 't', obj.t); + end + + function obj = step(obj) + obj.v = time.rk.rungekuttaRV(obj.v, obj.t, obj.k, obj.F, obj.RV, obj.coeffs); + obj.t = obj.t + obj.k; + obj.n = obj.n + 1; + end + end + + + methods (Static) + function k = getTimeStep(lambda) + k = rk4.get_rk4_time_step(lambda); + end + end + +end \ No newline at end of file