java - 如何在 Apache Commons Math SimplexSolver 中设置决策变量类型，如 binary、int、double？

如何在 Apache Commons Math int 中设置决策变量类型，如 binary、double、SimplexSolver？下面程序的输出是这样的:

332.6666666666667
1.0
8331.666666666668

我希望决策变量的类型为 int 而不是 double ；如果作为整数决策变量求解，则输出应为 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());
}

最佳答案

NumberFormat 对此很方便:

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

附录:此方法假设 simplex algorithm 是使用实数应用的，并且结果四舍五入为整数。包含 SimplexSolver org.apache.commons.math.optimization.linear 的包不提供其他实现。作为替代方案，考虑 different approach 或 Maxtrix<Rational> ，在 JScience 中可用。

关于java - 如何在 Apache Commons Math SimplexSolver 中设置决策变量类型，如 binary、int、double？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/7941182/