sos.m

function sos()
% Copyright 2024, Gurobi Optimization, LLC
%
% This example creates a very simple Special Ordered Set (SOS)
% model. The model consists of 3 continuous variables, no linear
% constraints, and a pair of SOS constraints of type 1.

model.ub = [1 1 2];
model.obj = [2 1 1];
model.modelsense = 'Max';
model.A = sparse(1,3);
model.rhs = 0;
model.sense = '=';

% Add first SOS: x1 = 0 or x2 = 0
model.sos(1).type   = 1;
model.sos(1).index  = [1 2];
model.sos(1).weight = [1 2];

% Add second SOS: x1 = 0 or x3 = 0
model.sos(2).type   = 1;
model.sos(2).index  = [1 3];
model.sos(2).weight = [1 2];

% Write model to file
gurobi_write(model, 'sos.lp');

result = gurobi(model);

for i=1:3
    fprintf('x%d %e\n', i, result.x(i))
end

fprintf('Obj: %e\n', result.objval);
end