使用Boost Graph库read_graphml函数读取GraphML属性时遇报错

问题 #

使用Boost库的read_graphml函数读取.graphml文件时，遇到属性找不到的错误。报错信息如下：

terminate called after throwing an instance of 'boost::wrapexcept<boost::property_not_found>'
  what():  Property not found: betti.
Aborted (core dumped)

最小可复现代码：

#include <iostream>
#include <fstream>
#include <boost/graph/graphml.hpp>
#include <boost/property_map/dynamic_property_map.hpp>

using namespace boost;

int main(int, char**){

    typedef adjacency_list<vecS, setS, undirectedS> Graph;


    std::ifstream graph_file;
    graph_file.open("more_exampleHoles_8.graphml", std::ifstream::in);

    Graph g;
    boost::dynamic_properties dp;
    boost::read_graphml(graph_file, g, dp);
}

目标GraphML文件内容：

<?xml version='1.0' encoding='UTF-8'?>
<!-- created by IGraph/M, http://szhorvat.net/mathematica/IGraphM -->
<graphml xmlns='http://graphml.graphdrawing.org/xmlns'
    xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
    xsi:schemaLocation='http://graphml.graphdrawing.org/xmlns http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd'>
 <key id="v_betti"
     for="node"
     attr.name="betti"
     attr.type="long" />
 <key for='node'
     id='v_dimk'
     attr.name='dimk'
     attr.type='long' />
 <key for='node'
     id='v_gap'
     attr.name='gap'
     attr.type='double' />
 <graph id='Graph'
     edgedefault='undirected'>
  <node id="1">
   <data key="v_betti">5</data>
   <data key='v_dimk'>1</data>
   <data key='v_gap'>0.12405641442417092</data>
  </node>
  <node id='2' />
  <node id='3' />
  <node id='4' />
  <node id='5' />
  <node id='6' />
  <node id='7' />
  <node id='8' />
  <node id='9' />
  <node id='10' />
  <node id='11' />
  <node id='12' />
  <edge source='1'
      target='2' />
  <edge source='1'
      target='3' />
  <edge source='1'
      target='4' />
  <edge source='1'
      target='8' />
  <edge source='2'
      target='7' />
  <edge source='2'
      target='9' />
  <edge source='2'
      target='11' />
  <edge source='3'
      target='5' />
  <edge source='3'
      target='10' />
  <edge source='4'
      target='5' />
  <edge source='4'
      target='6' />
  <edge source='4'
      target='7' />
  <edge source='4'
      target='8' />
  <edge source='4'
      target='9' />
  <edge source='4'
      target='11' />
  <edge source='5'
      target='9' />
  <edge source='5'
      target='10' />
  <edge source='6'
      target='8' />
  <edge source='7'
      target='10' />
  <edge source='8'
      target='10' />
  <edge source='9'
      target='11' />
 </graph>
</graphml>

解决方法 #

报错原因是read_graphml尝试读取GraphML中的节点属性，但未在dynamic_properties对象中为这些属性注册对应的属性映射。需要修改代码，定义包含节点属性的图类型，并将属性映射添加到dynamic_properties中。

修改后的代码 #

#include <iostream>
#include <fstream>
#include <boost/graph/graphml.hpp>
#include <boost/property_map/dynamic_property_map.hpp>
#include <boost/graph/adjacency_list.hpp>

using namespace boost;

// 定义节点属性结构体
struct NodeProperties {
    long betti;
    long dimk;
    double gap;
};

// 定义包含节点属性的图类型
typedef adjacency_list<vecS, setS, undirectedS, NodeProperties> Graph;

int main(int, char**){
    std::ifstream graph_file("more_exampleHoles_8.graphml", std::ifstream::in);

    Graph g;
    boost::dynamic_properties dp;

    // 将节点属性映射到dynamic_properties
    dp.property("betti", get(&NodeProperties::betti, g));
    dp.property("dimk", get(&NodeProperties::dimk, g));
    dp.property("gap", get(&NodeProperties::gap, g));

    // 读取GraphML文件，允许部分节点没有属性（使用默认值）
    boost::read_graphml(graph_file, g, dp, true);

    // 示例：输出第一个节点的属性
    auto v = *vertices(g).first;
    std::cout << "Node betti: " << g[v].betti << std::endl;
    std::cout << "Node dimk: " << g[v].dimk << std::endl;
    std::cout << "Node gap: " << g[v].gap << std::endl;

    return 0;
}

关键说明 #

• 定义NodeProperties结构体，对应GraphML中所有节点属性的类型和名称；
• 在adjacency_list的第四个模板参数中指定节点属性类型，让图结构能存储这些属性；
• 用dp.property()将GraphML中的属性名（对应attr.name）绑定到图的属性映射上；
• 调用read_graphml时最后一个参数设为true，允许部分节点无属性值，此时会使用属性类型的默认构造值（如long默认0，double默认0.0）。

内容的提问来源于stack exchange，提问作者ibnyusuf