使用Cplex在Java中定义二进制决策变量 [英] Defining a binary decision variable in java using cplex

问题描述

我正在尝试使用cplex在Java中定义一个二进制决策变量。那是一个二维变量。这意味着，如果路径从特定站点开始，则应该为1，否则为0。我有一组站点J和一组路径K，我的决策变量为Z_jk。目前，我正在按照以下方式定义代码，但无法正常工作。

I am trying to define a binary decision variable in java using cplex. That's a two dimensional variable. It means that if a path starts from a specific station it should be 1 or otherwise 0. I have a set of station, J and a set of paths, K and my decision variable is Z_jk. Currently I am defining the code like following, but it doesn't work. Could anybody please help me?

预先感谢。

// define variables
                z = new IloNumVar[stations_start.size()][];
                for (int j=0; j<stations_start.size();j++) {
                    z[j] = cplex.numVarArray(paths.size(),0,1);
                    for (int k=0;k<paths.size();k++) {
                        z[j][k] = cplex.numVar(new_column, 0, 1,"z");
                        z[j][k].setName("z."+j+"."+k);  
                    }   
                }

推荐答案

您正在尝试创建二进制决策变量的二维数组。您会遇到什么错误？

You are trying to create a 2D array of binary decision variables. What errors are you getting?

尝试查看CPLEX随附的一些示例代码。参见例如transport.java，其中包括一些这样声明和初始化的变量二维数组：

Try looking at some of the sample code provided with CPLEX. See for example transport.java which includes some 2D arrays of variables declared and initialised like this:

    IloNumVar[][] x = new IloNumVar[nbSupply][];
    IloNumVar[][] y = new IloNumVar[nbSupply][];

    for (int i = 0; i < nbSupply; i++) {
       x[i] = cplex.numVarArray(nbDemand, 0., Double.MAX_VALUE);
       y[i] = cplex.numVarArray(nbDemand, 0., Double.MAX_VALUE);
    } 

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