--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+rv/+time/RungekuttaRv.m	Fri Jul 05 17:47:13 2019 +0200
@@ -0,0 +1,57 @@
+classdef RungekuttaRv < time.Timestepper
+    properties
+        F         % RHS of the ODE
+        k       % Time step
+        t       % Time point
+        v       % Solution vector
+        n       % Time level
+        rkScheme  % The particular RK scheme used for time integration
+        RV              % Residual Viscosity operator
+        DvDt            % Function for computing the time deriative used for the RV evaluation
+    end
+    methods
+
+        function obj = RungekuttaRv(F, k, t0, v0, RV, DvDt, order)
+            obj.F = F;
+            obj.k = k;
+            obj.t = t0;
+            obj.v = v0;
+            obj.n = 0;
+            
+            if (order == 4) % Use specialized RK4 scheme
+                obj.rkScheme = @time.rk.rungekutta_4;
+            else
+                % Extract the coefficients for the specified order
+                % used for the RK updates from the Butcher tableua.
+                [s,a,b,c] = time.rk.butcherTableau(order);
+                coeffs = struct('s',s,'a',a,'b',b,'c',c);
+                obj.rkScheme = @(v,t,dt,F) time.rk.rungekutta(v, t , dt, F, coeffs);
+            end
+        
+            obj.RV = RV;
+            obj.DvDt = DvDt;
+        end
+
+        function [v, t] = getV(obj)
+            v = obj.v;
+            t = obj.t;
+        end
+
+        function state = getState(obj)
+            dvdt = obj.DvDt(obj.v);
+            [viscosity, Df, firstOrderViscosity, residualViscosity] = obj.RV.evaluate(obj.v, dvdt);
+            state = struct('v', obj.v, 'dvdt', dvdt, 'Df', Df, 'viscosity', viscosity, 'residualViscosity', residualViscosity, 'firstOrderViscosity', firstOrderViscosity, 't', obj.t);
+        end
+
+        % Advances the solution vector one time step using the Runge-Kutta method given by
+        % obj.coeffs, using a fixed residual viscosity for the Runge-Kutta substeps
+        function obj = step(obj)
+            % Fix the viscosity of the stabilized RHS
+            m = length(obj.v);
+            F = @(v,t) obj.F(v,t,spdiags(obj.RV.evaluateViscosity(obj.v, obj.DvDt(obj.v)),0,m,m));
+            obj.v = obj.rkScheme(obj.v, obj.t, obj.k, F);   
+            obj.t = obj.t + obj.k;
+            obj.n = obj.n + 1;
+        end
+    end
+end
\ No newline at end of file