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annotate minors.m @ 571:38c3da9675a5 feature/utux2D

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Bug fixes in scheme.Utux
author Martin Almquist <martin.almquist@it.uu.se>
date Tue, 22 Aug 2017 13:53:31 +0200
parents eaf557023fbe
children
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eaf557023fbe Added verbose flag to semiDefIneq and minors.
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1 function [minor, sub] = minors(A, verbose)
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2 default_arg('verbose', true);
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3 [n, m] = size(A);
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4
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5 if n ~= m
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6 error('A must be square');
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7 end
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8
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9 sub = {};
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10 ks = {};
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11
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12 ind = 1:n;
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13 for k = 1:n
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14 C = nchoosek(ind,k);
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15 for i = 1:size(C,1)
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16 ks{end + 1} = k;
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17 sub{end + 1} = A(C(i,:),C(i,:));
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18 end
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19 end
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20
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21 for i = 1:length(sub)
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22 if verbose
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23 fprintf('%d:\n', ks{i});
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24 disp(sub{i})
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25 end
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27 minor(i) = det(sub{i});
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28 end
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29 end
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32 % A is positive semidefinite if all minors are non-negative
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33 % A is negative semidefinite if all odd minors are non-positive and all even minors are non-negative
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34