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comparison +rv/+time/RungekuttaRvMultiGrid.m @ 1174:b96b1245a77d feature/rv

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Update variable names and comments in RungekuttaRvMultiGrid
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Fri, 28 Jun 2019 13:33:49 +0200
parents d02e5b8a0b24
children ebec2b86f539
comparison
equal deleted inserted replaced
1173:dde29b865244 1174:b96b1245a77d
7 v % Solution vector 7 v % Solution vector
8 n % Time level 8 n % Time level
9 rkScheme % The particular RK scheme used for time integration 9 rkScheme % The particular RK scheme used for time integration
10 RV % Residual Viscosity operator 10 RV % Residual Viscosity operator
11 DvDt % Function for computing the time deriative used for the RV evaluation 11 DvDt % Function for computing the time deriative used for the RV evaluation
12 v_unstable 12 v_coarse
13 viscosity 13 viscosity
14 end 14 end
15 methods 15 methods
16 16
17 function obj = RungekuttaRvMultiGrid(F, F_coarse, k, t0, v0, RV, DvDt, order) 17 function obj = RungekuttaRvMultiGrid(F, F_coarse, k, t0, v0, RV, DvDt, order)
32 obj.rkScheme = @(v,t,dt,F) time.rk.rungekutta(v, t , dt, F, coeffs); 32 obj.rkScheme = @(v,t,dt,F) time.rk.rungekutta(v, t , dt, F, coeffs);
33 end 33 end
34 34
35 obj.RV = RV; 35 obj.RV = RV;
36 obj.DvDt = DvDt; 36 obj.DvDt = DvDt;
37 obj.v_unstable = 0*v0; 37 obj.v_coarse = 0*v0;
38 obj.viscosity = 0*v0; 38 obj.viscosity = 0*v0;
39 end 39 end
40 40
41 function [v, t] = getV(obj) 41 function [v, t] = getV(obj)
42 v = obj.v; 42 v = obj.v;
43 t = obj.t; 43 t = obj.t;
44 end 44 end
45 45
46 function state = getState(obj) 46 function state = getState(obj)
47 dvdt = obj.DvDt(obj.v_unstable); 47 dvdt = obj.DvDt(obj.v_coarse);
48 [viscosity, Df, firstOrderViscosity, residualViscosity] = obj.RV.evaluate(obj.v, dvdt); 48 [viscosity, Df, firstOrderViscosity, residualViscosity] = obj.RV.evaluate(obj.v, dvdt);
49 state = struct('v', obj.v, 'dvdt', dvdt, 'Df', Df, 'viscosity', obj.viscosity, 'residualViscosity', residualViscosity, 'firstOrderViscosity', firstOrderViscosity, 't', obj.t); 49 state = struct('v', obj.v, 'dvdt', dvdt, 'Df', Df, 'viscosity', obj.viscosity, 'residualViscosity', residualViscosity, 'firstOrderViscosity', firstOrderViscosity, 't', obj.t);
50 end 50 end
51 51
52 % Advances the solution vector one time step using the Runge-Kutta method given by 52 % Advances the solution vector one time step using the Runge-Kutta method given by
53 % obj.coeffs, using a fixed residual viscosity for the Runge-Kutta substeps 53 % obj.coeffs, using a fixed residual viscosity for the Runge-Kutta substeps
54 function obj = step(obj) 54 function obj = step(obj)
55 % Fix the viscosity of the stabilized RHS
55 m = length(obj.viscosity); 56 m = length(obj.viscosity);
56 obj.v_unstable = obj.rkScheme(obj.v, obj.t, obj.k, obj.F_coarse);
57 obj.viscosity = obj.RV.evaluateViscosity(obj.v, obj.DvDt(obj.v_unstable));
58 % Fix the viscosity of the stabilized RHS
59 F_stable = @(v,t) obj.F(v,t,spdiags(obj.viscosity,0,m,m)); 57 F_stable = @(v,t) obj.F(v,t,spdiags(obj.viscosity,0,m,m));
58 % Advance solution on unstabilized coarse mesh based on current solution
59 obj.v_coarse = obj.rkScheme(obj.v, obj.t, obj.k, obj.F_coarse);
60 % Advance solution on on stabilized mesh based on current viscosity
60 obj.v = obj.rkScheme(obj.v, obj.t, obj.k, F_stable); 61 obj.v = obj.rkScheme(obj.v, obj.t, obj.k, F_stable);
62 % Compute viscosity for the next time time level using the advanced solution
63 obj.viscosity = obj.RV.evaluateViscosity(obj.v, obj.DvDt(obj.v_coarse));
61 obj.t = obj.t + obj.k; 64 obj.t = obj.t + obj.k;
62 obj.n = obj.n + 1; 65 obj.n = obj.n + 1;
63 end 66 end
64 end 67 end
65 end 68 end