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view stencilEquation.m @ 1013:eb441fbdf379 feature/advectionRV

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Draft implementation of RungeKutta with exterior RV updates - Draft class RungeKuttaExteriorRV which updates the residual using a BDF approximation of the derivtive outside of the RK stages. - Draft class for BDF derivative
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Wed, 05 Dec 2018 15:04:44 +0100
parents 184833fe4c0e
children
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% Find the equation for the stencil for d^k/dx^k
function [A,b] = stencilEquation(k, offsets, order)
    q = sym('q', [1, length(offsets)]);

    p = 0:(order-1+k);

    v     = vandermonde(offsets, p);
    vdiff = vandermonde(      0, p-k);

    eq = q*v == vdiff;

    [A,b] = equationsToMatrix(eq, q);
end