annotate +time/+rk4/rungekutta_4.m @ 958:72cd29107a9a feature/poroelastic

Temporary changes in multiblock.DiffOp. Change traction operators in Elastic2dvariable to be true boundary operators. But adjoint FD conv test fails for dirichlet BC so need to debug!
author Martin Almquist <malmquist@stanford.edu>
date Wed, 05 Dec 2018 18:58:10 -0800
parents 48b6fb693025
children
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Jonatan Werpers <jonatan@werpers.com>
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1 % Takes one time step of size k using the rungekutta method
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2 % starting from v_0 and where the function F(v,t) gives the
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3 % time derivatives.
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4 function v = rungekutta_4(v, t , k, F)
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5 k1 = F(v ,t );
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6 k2 = F(v+0.5*k*k1,t+0.5*k);
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7 k3 = F(v+0.5*k*k2,t+0.5*k);
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8 k4 = F(v+ k*k3,t+ k);
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9 v = v + (1/6)*(k1+2*(k2+k3)+k4)*k;
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