Question

commons-math（ver.2.2）有一个LP求解器。

Here我找到了以下示例代码：

import java.util.ArrayList;
import java.util.Collection;

import org.apache.commons.math.optimization.GoalType;
import org.apache.commons.math.optimization.OptimizationException;
import org.apache.commons.math.optimization.RealPointValuePair;
import org.apache.commons.math.optimization.linear.LinearConstraint;
import org.apache.commons.math.optimization.linear.LinearObjectiveFunction;
import org.apache.commons.math.optimization.linear.Relationship;
import org.apache.commons.math.optimization.linear.SimplexSolver;

@SuppressWarnings("deprecation")
public class Main {
    @SuppressWarnings({ "rawtypes", "unchecked"})
    public static void main(String[] args) {
        //describe the optimization problem
        LinearObjectiveFunction f = new LinearObjectiveFunction(new double[] { 3, 5}, 0);

        Collection constraints = new ArrayList();
        constraints.add(new LinearConstraint(new double[] { 2, 8}, Relationship.LEQ, 13));
        constraints.add(new LinearConstraint(new double[] { 5, -1}, Relationship.LEQ, 11));

        constraints.add(new LinearConstraint(new double[] { 1, 0}, Relationship.GEQ, 0));
        constraints.add(new LinearConstraint(new double[] { 0, 1}, Relationship.GEQ, 0));

        //create and run solver
        RealPointValuePair solution = null;
        try {
            solution = new SimplexSolver().optimize(f, constraints, GoalType.MAXIMIZE, false);
        }
        catch (OptimizationException e) {
            e.printStackTrace();
        }

        if (solution != null) {
            //get solution
            double max = solution.getValue();
            System.out.println("Opt: " + max);

            //print decision variables
            for (int i = 0; i < 2; i++) {
                System.out.print(solution.getPoint()[i] + "\t");
            }
        }
    }
}

但是，在添加最新数学版本（3.6.1）

的maven依赖项时

我看到大多数相关的类都已弃用，我还没有找到更新版本的代码示例。

很高兴使用3.6.1解决我的LP问题 - 有人可以在这里协助吗？

Answer 1

该链接的示例是使用 commons-math 版本2.

来自公共数学的主程序包似乎在版本3中从版本2 org.apache.commons.math更改为org.apache.commons.math3。

示例中使用的类来自org.apache.commons.math.optimization包，在这个具体案例中，新版本中的包是org.apache.commons.math3.optim。

从版本2到版本3的示例代码如下所示：

package commons.math;

import java.util.ArrayList;
import java.util.Collection;

import org.apache.commons.math3.optim.PointValuePair;
import org.apache.commons.math3.optim.linear.LinearConstraint;
import org.apache.commons.math3.optim.linear.LinearConstraintSet;
import org.apache.commons.math3.optim.linear.LinearObjectiveFunction;
import org.apache.commons.math3.optim.linear.Relationship;
import org.apache.commons.math3.optim.linear.SimplexSolver;
import org.apache.commons.math3.optim.nonlinear.scalar.GoalType;

public class MathTest {

    public static void main(String[] args) {
        //describe the optimization problem
        LinearObjectiveFunction f = new LinearObjectiveFunction(new double[] { 3, 5}, 0);

        Collection<LinearConstraint> constraints = new ArrayList<LinearConstraint>();
        constraints.add(new LinearConstraint(new double[] { 2, 8}, Relationship.LEQ, 13));
        constraints.add(new LinearConstraint(new double[] { 5, -1}, Relationship.LEQ, 11));

        constraints.add(new LinearConstraint(new double[] { 1, 0}, Relationship.GEQ, 0));
        constraints.add(new LinearConstraint(new double[] { 0, 1}, Relationship.GEQ, 0));

        //create and run solver
        PointValuePair solution = null;
        solution = new SimplexSolver().optimize(f, new LinearConstraintSet(constraints), GoalType.MAXIMIZE);

        if (solution != null) {
            //get solution
            double max = solution.getValue();
            System.out.println("Opt: " + max);

            //print decision variables
            for (int i = 0; i < 2; i++) {
                System.out.print(solution.getPoint()[i] + "\t");
            }
        }
    }
}

希望它有所帮助，

apache.commons.math3 - 如何使用线性编程？

1 个答案: