40 lines
961 B
Mathematica
40 lines
961 B
Mathematica
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function F = exclude(X,Y)
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%EXCLUDE Excludes a binary solution
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%
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% F = exclude(X,value)
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%
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%EXCLUDE is used to avoid a particular binary solution. This can be used
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% to repeatedly solve MILP problems while exluding all past solutions
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%
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% A = randn(30,15);
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% b = 25*rand(30,1);
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% c = randn(15,1);
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% x = binvar(15,1);
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% Model = A*x <= b;
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% sol = solvesdp(Model,c'*x);
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% while sol.problem == 0
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% Model = [Model, exclude(x,double(x))];
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% sol = solvesdp(Model,c'*x);
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% end
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if isa(X,'sdpvar') & is(X,'binary') & isnumeric(Y) & ismember(Y,[0 1])
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if isequal(size(X),size(Y))
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else
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error('Dimension mismatch in EXCLUDE')
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end
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zv = find((Y == 0));
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ov = find((Y == 1));
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lhs = 0;
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if ~isempty(zv)
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lhs = lhs + sum(extsubsref(X,zv));
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end
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if ~isempty(ov)
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lhs = lhs + sum(1-extsubsref(X,ov));
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end
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F = [lhs >=1];
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else
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error('EXCLUDE only applicable to binary variables and data');
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end
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