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view minors.m @ 1031:2ef20d00b386 feature/advectionRV
For easier comparison, return both the first order and residual viscosity when evaluating the residual. Add the first order and residual viscosity to the state of the RungekuttaRV time steppers
author | Vidar Stiernström <vidar.stiernstrom@it.uu.se> |
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date | Thu, 17 Jan 2019 10:25:06 +0100 |
parents | eaf557023fbe |
children |
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function [minor, sub] = minors(A, verbose) default_arg('verbose', true); [n, m] = size(A); if n ~= m error('A must be square'); end sub = {}; ks = {}; ind = 1:n; for k = 1:n C = nchoosek(ind,k); for i = 1:size(C,1) ks{end + 1} = k; sub{end + 1} = A(C(i,:),C(i,:)); end end for i = 1:length(sub) if verbose fprintf('%d:\n', ks{i}); disp(sub{i}) end minor(i) = det(sub{i}); end end % A is positive semidefinite if all minors are non-negative % A is negative semidefinite if all odd minors are non-positive and all even minors are non-negative