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comparison +util/tt2t.m @ 0:48b6fb693025

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Initial commit.
author Jonatan Werpers <jonatan@werpers.com>
date Thu, 17 Sep 2015 10:12:50 +0200
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-1:000000000000 0:48b6fb693025
1 % Converts a semidiscretized PDE from second order in time to first order in time.
2 % v_tt = Dv + S
3 % becomes
4 % w_t = Mw + C
5 % where
6 % w = [ v ; v_t]
7 % and
8 % M = [0 I;
9 % D 0];
10 % C = [0;
11 % S];
12 function [M,C] = tt2t(D,S)
13 default_arg('S',sparse(size(D)))
14 time_dependent_bc = isa(S,'function_handle');
15
16 I = eye(size(D));
17 O = zeros(size(D));
18
19 M = [O I;
20 D O];
21
22 if ~time_dependent_bc
23 C = [zeros(size(S)); S];
24 else
25 o = zeros(size(S(0)));
26 C = @(t)([o; S(t)]);
27 end
28 end