view +time/Rungekutta4proper.m @ 1198:2924b3a9b921 feature/d2_compatible

Add OpSet for fully compatible D2Variable, created from regular D2Variable by replacing d1 by first row of D1. Formal reduction by one order of accuracy at the boundary point.
author Martin Almquist <malmquist@stanford.edu>
date Fri, 16 Aug 2019 14:30:28 -0700
parents e1a05acc1b5d
children c6fcee3fcf1b 8894e9c49e40
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classdef Rungekutta4proper < time.Timestepper
    properties
        F
        k
        t
        v
        m
        n
    end


    methods
        % Timesteps v_t = F(v,t), using RK4 fromt t = t0 with timestep k and initial conditions v = v0
        function obj = Rungekutta4proper(F, k, t0, v0)
            obj.F = F;
            obj.k = k;
            obj.t = t0;
            obj.v = v0;
            obj.m = length(v0);
            obj.n = 0;
        end

        function [v,t] = getV(obj)
            v = obj.v;
            t = obj.t;
        end

        function obj = step(obj)
            obj.v = time.rk4.rungekutta_4(obj.v, obj.t, obj.k, obj.F);
            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