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annotate findZeros.m @ 1037:2d7ba44340d0 feature/burgers1d

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Pass scheme specific parameters as cell array. This will enabale constructDiffOps to be more general. In addition, allow for schemes returning function handles as diffOps, which is currently how non-linear schemes such as Burgers1d are implemented.
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Fri, 18 Jan 2019 09:02:02 +0100
parents 8368beb0d1b3
children
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8368beb0d1b3 Added function to calculate multiple solutions to an equation.
Jonatan Werpers <jonatan@werpers.com>
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1 % findZeros looks for solutions to the equation f(x)==0 within
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2 % the limits lim with a granularity of h.
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3 % Returns a sorted list of unique solutions.
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4 function z = findZeros(f, lim, h)
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5 n = ceil((lim(2)-lim(1))/h);
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6 z0 = linspace(lim(1), lim(2), n);
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7
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8 z = zeros(1,n);
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9
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10 for i = 1:n
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11 zt(i) = fzero(f, z0(i));
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12 end
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13
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14 zt = sort(zt);
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16 z = [];
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17 for i = 1:n
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18 if zt(i) < lim(1) || zt(i) > lim(2)
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19 continue
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20 end
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21
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22 if ~isempty(z) && abs(z(end) - zt(i)) < 1e-6
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23 continue
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24 end
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25
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26 z = [z zt(i)];
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27 end
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28
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29 % z = unique(z);
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30 end