c++ - Boost::Graph 中的 read_graphviz()，传递给构造函数

Question

我使用 python 库生成了以下 GraphViz .dot 文件。

http://pastebin.com/mL7ck9Zp

我现在想将它读入 C++ 的 Boost::Graph，以便我可以在其上使用 Boost::Graph 的库算法。

但是，我需要做一些预处理。特别是，我想创建一个带有字符串构造函数的捆绑属性，并让 read_graphviz() 将点文件中标签字段中的字符串传递给字符串构造函数。

我该怎么做？

Answer 1

首先要意识到的是，Boost 文档示例几乎总是引用/从实际示例生成:libs/graph/example/read_graphviz.cpp

要认识到的第二件事是 BGL 是高度通用的。高度。它在 Boost Property Maps 的概念上实现了大部分通用性.

最后，观察从“自由格式”(至少动态/无类型文本格式)解析为某种通用 MutableGraph模型正在挑战极限。

这解释了您必须如何阅读 the docs for property_map 下文档的重要部分.

无论如何，因为确实the sample似乎有点过时了，请允许我演示一下:

1. 将解析器的实现包含在一个翻译单元中:

   #include <libs/graph/src/read_graphviz_new.cpp>
   

   这样 BGL 仍然是一个只有头文件的库。

2. 现在更喜欢捆绑属性:

   struct Vertex {
       std::string name, label, shape;
   };
   
   struct Edge {
       std::string label;
       double weight; // perhaps you need this later as well, just an example
   };
   
   typedef property<graph_name_t, std::string> graph_p;
   typedef adjacency_list<vecS, vecS, directedS, Vertex, Edge, graph_p> graph_t;
   

   我们将为顶点和边填充label、shape、name。

3. 动态属性映射是魔法发生的地方:

   dynamic_properties dp/*(ignore_other_properties)*/;
   

   此类提供对各种底层的类型删除访问 property maps由 (name, typeid(key_type)) 标识。

   这意味着您可以注册捆绑属性，并将它们映射到 graphviz 属性名称:

   int main() {
       // Construct an empty graph and prepare the dynamic_property_maps.
       graph_t graph(0);
   
       dynamic_properties dp(ignore_other_properties);
       dp.property("node_id", get(&Vertex::name,  graph));
       dp.property("label",   get(&Vertex::label, graph));
       dp.property("shape",   get(&Vertex::shape, graph));
       dp.property("label",   get(&Edge::label,   graph));
   

   That's really all there is to it. (Read up on the magic of Bundled Properties, found via the page for the adjacency_list template).

   虽然我们不需要它，但让我们也将 graph 属性加入其中(如文档示例中所示):

       // Use ref_property_map to turn a graph property into a property map
       boost::ref_property_map<graph_t *, std::string> gname(get_property(graph, graph_name));
       dp.property("name",    gname);
   

4. 现在剩下的就是阅读图表了。

   嗯。好吧。让我们也把它写回来，但是用一个新的图形名称，然后:

   std::ifstream dot("input.dot");
   
   if (read_graphviz(dot, graph, dp/*, "node_id"*/)) {
       std::cout << "Graph name: '" << get_property(graph, graph_name) << "'\n";
       get_property(graph, graph_name) = "Let's give it a name";
       write_graphviz_dp(std::cout, graph, dp/*, "node_id"*/);
   }
   

5. 不要忘记链接到 Boost Regex

完整演示

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#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/graphviz.hpp>
#include <boost/property_map/dynamic_property_map.hpp>
#include <libs/graph/src/read_graphviz_new.cpp>
#include <boost/graph/graph_utility.hpp>

using namespace boost;

struct Vertex {
    std::string name, label, shape;
};

struct Edge {
    std::string label;
    double weight; // perhaps you need this later as well, just an example
};

typedef property<graph_name_t, std::string> graph_p;
typedef adjacency_list<vecS, vecS, directedS, Vertex, Edge, graph_p> graph_t;

int main() {
    // Construct an empty graph and prepare the dynamic_property_maps.
    graph_t graph(0);

    dynamic_properties dp/*(ignore_other_properties)*/;
    dp.property("node_id", get(&Vertex::name,  graph));
    dp.property("label",   get(&Vertex::label, graph));
    dp.property("shape",   get(&Vertex::shape, graph));
    dp.property("label",   get(&Edge::label,   graph));

    // Use ref_property_map to turn a graph property into a property map
    boost::ref_property_map<graph_t *, std::string> gname(get_property(graph, graph_name));
    dp.property("name",    gname);

    std::ifstream dot("input.dot");

    if (read_graphviz(dot, graph, dp/*, "node_id"*/)) {
        std::cout << "Graph name: '" << get_property(graph, graph_name) << "'\n";
        get_property(graph, graph_name) = "Let's give it a name";
        write_graphviz_dp(std::cout, graph, dp/*, "node_id"*/);
    }
}

打印(注意之前的空名称，以及之后更新的图形名称属性):

Graph name: ''
digraph G {
name="Let's give it a name";
n0 [label="A9\n", shape=box];
n1 [label="- [0.48%,19.42%]", shape=ellipse];
n11 [label="+ [0%,0%]", shape=ellipse];
n12 [label="- [0%,0.75%]", shape=ellipse];
n13 [label="+ [0.03%,1.33%]", shape=ellipse];
n14 [label="- [0%,0.75%]", shape=ellipse];
n15 [label="+ [0%,0%]", shape=ellipse];
n16 [label="+ [0%,0%]", shape=ellipse];
n17 [label="A14\n", shape=box];
n18 [label="+ [0.03%,2.51%]", shape=ellipse];
n19 [label="A15\n", shape=box];
n2 [label="A15\n", shape=box];
n20 [label="A6\n", shape=box];
n21 [label="A2\n", shape=box];
n22 [label="- [0%,1.11%]", shape=ellipse];
n23 [label="+ [0%,1%]", shape=ellipse];
n25 [label="- [0%,2.18%]", shape=ellipse];
n26 [label="+ [0%,1.79%]", shape=ellipse];
n27 [label="- [0%,1%]", shape=ellipse];
n28 [label="- [0%,0%]", shape=ellipse];
n29 [label="- [0%,0%]", shape=ellipse];
n3 [label="A11\n", shape=box];
n30 [label="- [0%,0%]", shape=ellipse];
n31 [label="- [0%,0%]", shape=ellipse];
n32 [label="- [0%,1%]", shape=ellipse];
n33 [label="A13\n", shape=box];
n34 [label="+ [0%,1%]", shape=ellipse];
n35 [label="- [0%,0%]", shape=ellipse];
n36 [label="- [0.01%,1.21%]", shape=ellipse];
n38 [label="A12\n", shape=box];
n39 [label="- [0%,1%]", shape=ellipse];
n4 [label="A4\n", shape=box];
n40 [label="+ [0%,1.17%]", shape=ellipse];
n42 [label="- [0%,0%]", shape=ellipse];
n43 [label="A12\n", shape=box];
n44 [label="+ [0%,1.11%]", shape=ellipse];
n45 [label="- [0%,1%]", shape=ellipse];
n47 [label="- [0%,0%]", shape=ellipse];
n49 [label="+ [0%,1.17%]", shape=ellipse];
n5 [label="+ [0%,0%]", shape=ellipse];
n52 [label="+ [0%,0.75%]", shape=ellipse];
n54 [label="A13\n", shape=box];
n55 [label="A14\n", shape=box];
n56 [label="- [0.03%,2.5%]", shape=ellipse];
n57 [label="+ [0.01%,2.27%]", shape=ellipse];
n59 [label="- [0%,0%]", shape=ellipse];
n6 [label="A7\n", shape=box];
n60 [label="+ [0%,1%]", shape=ellipse];
n63 [label="A15\n", shape=box];
n64 [label="+ [0.05%,1.34%]", shape=ellipse];
n65 [label="A15\n", shape=box];
n66 [label="- [0%,1%]", shape=ellipse];
n67 [label="+ [0.02%,2.44%]", shape=ellipse];
n7 [label="A14\n", shape=box];
n71 [label="+ [0.21%,3.83%]", shape=ellipse];
n8 [label="+ [0%,1.57%]", shape=ellipse];
n9 [label="- [0.01%,1.22%]", shape=ellipse];
n0->n1  [label=f];
n0->n2  [label=t];
n17->n18  [label="<=110"];
n17->n19  [label=">110"];
n19->n20  [label="<=8"];
n19->n49  [label=">8"];
n2->n3  [label="<=228"];
n2->n71  [label=">228"];
n20->n21  [label=aa];
n20->n25  [label=c];
n20->n26  [label=cc];
n20->n27  [label=d];
n20->n28  [label=e];
n20->n29  [label=ff];
n20->n30  [label=i];
n20->n31  [label=j];
n20->n32  [label=k];
n20->n33  [label=m];
n20->n38  [label=q];
n20->n42  [label=r];
n20->n43  [label=w];
n20->n47  [label=x];
n21->n22  [label="<=41"];
n21->n23  [label=">41"];
n3->n4  [label="<=3"];
n3->n63  [label=">3"];
n33->n34  [label=g];
n33->n35  [label=p];
n33->n36  [label=s];
n38->n39  [label=f];
n38->n40  [label=t];
n4->n5  [label=l];
n4->n6  [label=u];
n4->n54  [label=y];
n43->n44  [label=f];
n43->n45  [label=t];
n54->n55  [label=g];
n54->n59  [label=p];
n54->n60  [label=s];
n55->n56  [label="<=204"];
n55->n57  [label=">204"];
n6->n7  [label=bb];
n6->n11  [label=dd];
n6->n12  [label=ff];
n6->n13  [label=h];
n6->n14  [label=j];
n6->n15  [label=n];
n6->n16  [label=o];
n6->n17  [label=v];
n6->n52  [label=z];
n63->n64  [label="<=4"];
n63->n65  [label=">4"];
n65->n66  [label="<=5"];
n65->n67  [label=">5"];
n7->n8  [label="<=164"];
n7->n9  [label=">164"];
}