Glpk java 和 .mod 文件

Question

我有一个 .mod 文件，我可以在 java（使用 netbeans）中运行它。该文件从另一个文件 .dat 中获取数据，因为开发它的人使用的是 GUSEK。现在我们需要在java中实现它，但我不知道如何将数据放入.mod文件中的K常数。

无所谓方式，可以通过数据库查询或文件读取。

我对数学编程一无所知，我只需要为已经制作好的 glpk 函数添加值。

这是 .mod 函数：

# OPRE

set K;

param mc {k in K};
param phi {k in K};
param cman {k in K};
param ni {k in K};
param cesp;
param mf;

var x {k in K} binary;

minimize custo: sum {k in K} (mc[k]*phi[k]*(1-x[k]) + cman[k]*phi[k]*x[k]);

s.t. recursos: sum {k in K} (cman[k]*phi[k]*x[k]) - cesp <= 0;
s.t. ocorrencias: sum {k in K} (ni[k] + (1-x[k])*phi[k]) - mf <= 0;

end;

这里是 java 代码：

package br.com.genera.service.otimi;

import org.gnu.glpk.*;

public class Gmpl implements GlpkCallbackListener, GlpkTerminalListener {

    private boolean hookUsed = false;

    public static void main(String[] arg) {

        String[] nomeArquivo = new String[2];
        nomeArquivo[0] = "C:\PodaEquipamento.mod";

        System.out.println(nomeArquivo[0]);
        GLPK.glp_java_set_numeric_locale("C");
        System.out.println(nomeArquivo[0]);
        new Gmpl().solve(nomeArquivo);
    }

    public void solve(String[] arg) {
        glp_prob lp = null;
        glp_tran tran;
        glp_iocp iocp;

        String fname;
        int skip = 0;
        int ret;

        // listen to callbacks
        GlpkCallback.addListener(this);
        // listen to terminal output
        GlpkTerminal.addListener(this);

        fname = arg[0];

        lp = GLPK.glp_create_prob();
        System.out.println("Problem created");
        tran = GLPK.glp_mpl_alloc_wksp();
        ret = GLPK.glp_mpl_read_model(tran, fname, skip);
        if (ret != 0) {
            GLPK.glp_mpl_free_wksp(tran);
            GLPK.glp_delete_prob(lp);
            throw new RuntimeException("Model file not found: " + fname);
        }

        // generate model
        GLPK.glp_mpl_generate(tran, null);
        // build model
        GLPK.glp_mpl_build_prob(tran, lp);
        // set solver parameters
        iocp = new glp_iocp();
        GLPK.glp_init_iocp(iocp);
        iocp.setPresolve(GLPKConstants.GLP_ON);

        // do not listen to output anymore
        GlpkTerminal.removeListener(this);
        // solve model
        ret = GLPK.glp_intopt(lp, iocp);
        // postsolve model
        if (ret == 0) {
            GLPK.glp_mpl_postsolve(tran, lp, GLPKConstants.GLP_MIP);
        }
        // free memory
        GLPK.glp_mpl_free_wksp(tran);
        GLPK.glp_delete_prob(lp);

        // do not listen for callbacks anymore
        GlpkCallback.removeListener(this);

        // check that the hook function has been used for terminal output.
        if (!hookUsed) {
            System.out.println("Error: The terminal output hook was not used.");
            System.exit(1);
        }
    }

    @Override
    public boolean output(String str) {
        hookUsed = true;
        System.out.print(str);
        return false;
    }

    @Override
    public void callback(glp_tree tree) {
        int reason = GLPK.glp_ios_reason(tree);
        if (reason == GLPKConstants.GLP_IBINGO) {
            System.out.println("Better solution found");
        }
    }
}

我在控制台中得到了这个：

Reading model section from C:\PodaEquipamento.mod...
33 lines were read
Generating custo...
C:\PodaEquipamento.mod:24: no value for K
glp_mpl_build_prob: invalid call sequence

希望有人能帮忙，谢谢。

Answer 1

最好的方法是像读取模型文件一样读取数据文件。

ret = GLPK.glp_mpl_read_data(tran, fname_data, skip);
if (ret != 0) {
    GLPK.glp_mpl_free_wksp(tran);
    GLPK.glp_delete_prob(lp);
    throw new RuntimeException("Data file not found: " + fname_data);
}

Answer 2

我解决了将数据块从 .data 文件复制到 .mod 文件中的问题。

无论如何，谢谢 puhgee。

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