Choco Solver：如何使用真实变量和约束设置CSP

Question

我想写一个自动生成室内环境的程序。为此，我考虑了将问题表述为CSP的想法，其中变量为：

>

x_o，y_o：对象o在环境中的位置

θo：对象o的方向

和域是：

>

x和y的某个范围[a， b]（即2D网格的尺寸）

方向为[0,90180270]度。

为了实现这个问题，我在Eclipse4.7.1a中使用了Choco。

我的问题如下：

我想表达一个约束，比如：对象a在对象b前面。

由于物体有方向，我认为表达这种约束的一种可能方式是：

• x_b==x_a cos（θa）

从这个资源中，我发现Choco使用Ibex来解决实际的约束。我按照安装说明将共享库添加到java。图书馆路径。为了定义一个真正的约束，我遵循以下文档，但当我运行这段代码时：

import org.chocosolver.solver.Model;
import org.chocosolver.solver.Solution;
import org.chocosolver.solver.variables.RealVar;

public class EnvironmentGenerationMain {

    public static void main(String[] args) {
        Model model = new Model("Environment generation problem");
        System.out.println(model.getName());

        //A
        RealVar x_a = model.realVar("X_a", 0, 2, 1.0d);
        RealVar y_a = model.realVar("Y_a", 0, 2, 1.0d);
        RealVar z_a = model.realVar("Z_a", 0, 270, 90.0d);

        //A
        RealVar x_b = model.realVar("X_b", 0, 2, 1.0d);
        RealVar y_b = model.realVar("Y_b", 0, 2, 1.0d);
        RealVar z_b = model.realVar("Z_b", 0, 270, 90.0d);

        model.post(model.realIbexGenericConstraint("{0}={1}+cos{2}", x_b,x_a,z_a));
        model.post(model.realIbexGenericConstraint("{0}={1}+sin{2}", y_b,y_a,z_a));


        Solution solution = model.getSolver().findSolution();
        if(solution != null){
            System.out.println(solution.toString());
        }

    }

}

这是我得到的错误：

Environment generation problem
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007f7e322b0891, pid=21072, tid=0x00007f7e63562700
#
# JRE version: OpenJDK Runtime Environment (8.0_151-b12) (build 1.8.0_151-8u151-b12-0ubuntu0.16.04.2-b12)
# Java VM: OpenJDK 64-Bit Server VM (25.151-b12 mixed mode linux-amd64 compressed oops)
# Problematic frame:
# C  [libibex-java.so+0x4891]  Java_org_chocosolver_solver_constraints_real_Ibex_add_1ctr+0x61
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /home/dede/eclipse-workspace/EnvironmentGeneration/hs_err_pid21072.log
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#

我发现这是一个常见的问题：

写入核心转储失败。核心转储已被禁用

但是我在网上找到的答案都没有解决我的问题。

所以，如果有人能给我指出一个解决方案，我会非常高兴的！！！

谢谢

Answer 1

@托比：我在用Linux

升级到Choco 4.0.6和Ibex 2.6.3解决了这个问题。为了让事情顺利进行，我还必须调试代码。这是一个有效的例子：

package it.semanticmapping.environmentgeneration;

import org.chocosolver.solver.Model;
import org.chocosolver.solver.Solution;
import org.chocosolver.solver.variables.RealVar;

public class EnvironmentGenerationMain {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Model model = new Model("Environment Generation");
        System.out.println(model.getName());


        //A
        RealVar x_a = model.realVar("X_a", 0, 2, 0.0001d);
        RealVar y_a = model.realVar("Y_a", 0, 2, 0.0001d);
        RealVar z_a = model.realVar("Z_a", 0, Math.PI*3/2, Math.PI/2);

        //B
        RealVar x_b = model.realVar("X_b", 0, 2, 0.0001d);
        RealVar y_b = model.realVar("Y_b", 0, 2, 0.0001d);
        RealVar z_b = model.realVar("Z_b", 0, Math.PI*3/2, Math.PI/2);

        RealVar cost = model.realVar(0);

        model.post(model.realIbexGenericConstraint("{0}={1}", z_a,cost));
        model.post(model.realIbexGenericConstraint("{0}={1}+cos({2})", x_b,x_a,z_a));
        model.post(model.realIbexGenericConstraint("{0}={1}+sin({2})", y_b,y_a,z_a));
        model.post(model.realIbexGenericConstraint("{0}={1}", z_b, z_a));

        Solution solution = model.getSolver().findSolution();
        if(solution != null){
            System.out.println(solution.toString());
        }
    }

}