如何在Apache Commons Math SimplexSolver中設置二進制，整數，雙精度等決策變量類型？

Question

如何在Apache Commons Math SimplexSolver設置二進制， int ， double SimplexSolver等決策變量類型？ 以下程序的輸出如下：

332.6666666666667
1.0
8331.666666666668

我希望決策變量的類型為int而不是double ; 如果求解為整數決策變量333, 0, 8325則輸出應為333, 0, 8325 。

public static void testSample() throws OptimizationException {
    LinearObjectiveFunction f = new LinearObjectiveFunction(new double[]{25, 15}, 0);
    Collection<LinearConstraint> constraints = new ArrayList<LinearConstraint>();
    constraints.add(new LinearConstraint(new double[]{5, 8}, Relationship.LEQ, 5000));
    constraints.add(new LinearConstraint(new double[]{1, 4}, Relationship.LEQ, 1500));
    constraints.add(new LinearConstraint(new double[]{3, 2}, Relationship.LEQ, 1000));
    constraints.add(new LinearConstraint(new double[]{1, 0}, Relationship.GEQ, 1));
    constraints.add(new LinearConstraint(new double[]{0, 1}, Relationship.GEQ, 1));

    SimplexSolver solver = new SimplexSolver();
    RealPointValuePair solution = solver.optimize(f, constraints, GoalType.MAXIMIZE, true);

    System.out.println(solution.getPoint()[0]);
    System.out.println(solution.getPoint()[1]);
    System.out.println(solution.getValue());
}

Answer 1

NumberFormat很方便：

NumberFormat nf = NumberFormat.getIntegerInstance();
System.out.println(nf.format(solution.getPoint()[0]));
System.out.println(nf.format(solution.getPoint()[1]));
System.out.println(nf.format(solution.getValue()));

安慰：

333
1
8,332

附錄：此方法假設使用實數應用單純形算法 ，並將結果舍入為整數。 包含SimplexSolver的包， org.apache.commons.math.optimization.linear ，不提供其他實現。 作為替代方案，可以考慮不同的方法或Maxtrix<Rational>以可用JScience 。