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annotate +time/Rungekutta.m @ 1025:ac80bedc8df7 feature/advectionRV

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Clean up of Utux2d
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Mon, 07 Jan 2019 16:26:05 +0100
parents 4e5e53d6336c
children
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c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
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1 classdef Rungekutta < time.Timestepper
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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2 properties
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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3 F % RHS of the ODE
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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4 k % Time step
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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5 t % Time point
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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6 v % Solution vector
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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7 n % Time level
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4e5e53d6336c Correct documentation of Rungekutta
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8 scheme % The scheme used for the time stepping, e.g rk4, rk6 etc.
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c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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9 end
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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10
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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11
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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12 methods
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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13 % Timesteps v_t = F(v,t), using RK with specfied order from t = t0 with
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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14 % timestep k and initial conditions v = v0
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
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15 function obj = Rungekutta(F, k, t0, v0, order)
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1c6f1595bb94 Clean up in RK time stepper schemes
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
parents: 846
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16 default_arg('order',4);
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c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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17 obj.F = F;
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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18 obj.k = k;
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19 obj.t = t0;
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20 obj.v = v0;
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21 obj.n = 0;
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5b180c76578e Use the old implementation for RK4 until the different methods are profiled.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
parents: 847
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22 % TBD: Order 4 is also implemented in the butcher tableau, but the rungekutta_4.m implementation
5b180c76578e Use the old implementation for RK4 until the different methods are profiled.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
parents: 847
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23 % might be slightly more efficient. Need to do some profiling before deciding whether or not to keep it.
5b180c76578e Use the old implementation for RK4 until the different methods are profiled.
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24 if (order == 4)
5b180c76578e Use the old implementation for RK4 until the different methods are profiled.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
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25 obj.scheme = @time.rk.rungekutta_4;
5b180c76578e Use the old implementation for RK4 until the different methods are profiled.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
parents: 847
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26 else
5b180c76578e Use the old implementation for RK4 until the different methods are profiled.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
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27 % Extract the coefficients for the specified order
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Vidar Stiernström <vidar.stiernstrom@it.uu.se>
parents: 847
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28 % used for the RK updates from the Butcher tableua.
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Vidar Stiernström <vidar.stiernstrom@it.uu.se>
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29 [s,a,b,c] = time.rk.butcherTableau(order);
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parents: 847
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30 coeffs = struct('s',s,'a',a,'b',b,'c',c);
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31 obj.scheme = @(v,t,dt,F) time.rk.rungekutta(v, t , dt, F, coeffs);
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parents: 847
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32 end
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c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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33 end
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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34
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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35 function [v,t] = getV(obj)
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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36 v = obj.v;
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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37 t = obj.t;
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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38 end
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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39
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
Vidar Stiernström <vidar.stiernstrom@it.uu.se>
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40 function obj = step(obj)
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41 obj.v = obj.scheme(obj.v, obj.t, obj.k, obj.F);
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c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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42 obj.t = obj.t + obj.k;
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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43 obj.n = obj.n + 1;
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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44 end
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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45 end
c6fcee3fcf1b Add generalized RungeKutta and RungeKuttaRV class which extracts its coefficients from a butcher tableau, specified on the scheme.
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46 end